Squashed commit of the following:

commit 58dd2e30
Merge: cf6f0320 82a976e0
Author: Dennis Real <github@tildepipe.org>
Date:   Sat Mar 31 18:43:47 2012 +0200

    Merge branch 'master' of git://github.com/derf/feh

commit cf6f0320
Merge: 10b7b1e3 877e6346
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Mar 25 19:07:30 2012 +0200

    Merge branch 'master' of git://github.com/derf/feh

commit 10b7b1e3
Author: Dennis Real <github@tildepipe.org>
Date:   Sat Mar 24 14:41:15 2012 +0100

    Support for Canon Exif makernote tags

commit 3c284dc8
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:44:32 2012 +0100

    Support for Active D-Lightning

commit ad5aea8c
Merge: cc6de200 9c43b648
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:01:38 2012 +0100

    Merge remote branch 'upstream/master'

commit cc6de200
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:00:30 2012 +0100

    Nikon makernote parts changed

commit e401bd9c
Author: Dennis Real <github@tildepipe.org>
Date:   Wed Mar 21 19:47:15 2012 +0100

    1. Own module for nikon maker notes
    2. Support for AFInfo2

commit 39cbd1ed
Merge: 9e1bbf87 a1001232
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 22:22:28 2012 +0100

    Merge remote branch 'upstream/master'

commit 9e1bbf87
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 22:20:58 2012 +0100

    - exif handling changed
    - gps info added if available

commit 8e963828
Merge: 77fa5aca 29cd8688
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 19:13:47 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit 77fa5aca
Merge: 93a90e60 3b2756bf
Author: Dennis Real <github@tildepipe.org>
Date:   Wed Mar 7 17:18:07 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit 93a90e60
Merge: a81465d0 52d5da9c
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Mar 6 21:42:40 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit a81465d0
Merge: a19e50de 31afac45
Author: Dennis Real <github@tildepipe.org>
Date:   Mon Mar 5 17:23:40 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit a19e50de
Merge: 1c89da12 fe9a16bc
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Mar 4 15:35:45 2012 +0100

    Merge branch 'master' of ssh://github.com/reald/feh

commit 1c89da12
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:37:22 2012 +0100

    test case adapted to new testfile

commit bb3c9d35
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:34:51 2012 +0100

    test file with some exif data added

commit fe9a16bc
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:37:22 2012 +0100

    test case adapted to new testfile

commit e0bedc04
Merge: 46801fee 69ecc5c1
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:36:08 2012 +0100

    Merge remote branch 'upstream/master'

commit 46801fee
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:34:51 2012 +0100

    test file with some exif data added

Still to do: signal handler for sigint/quit/term

Problems so far:
* leaks zombie processes
* does not work when terminating feh with a signal (since the convert process
  is no longer in feh's process group)

commit 9c8226a1
Merge: e4483e5e 132ecc0f
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Feb 5 17:24:17 2012 +0100

    Merge branch 'master' of ssh://github.com/reald/feh

commit e4483e5e
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Feb 5 16:56:29 2012 +0100

    - improved handling of images which have exif tags but not ours
    - fixed uninitialized pointer in thumbnail mode
    - added nikon lens info if available

commit 132ecc0f
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Feb 5 16:56:29 2012 +0100

    - improved handling of images which have exif tags but not ours
    - fixed uninitialzed pointer in thumbnail mode
    - added nikon lens info if available

- fixed uninitialized pointer in thumbnail mode
- added nikon lens info if available

- fixed uninitialzed pointer in thumbnail mode
- added nikon lens info if available

Required e.g. for feh --preload --thumbnails

This fixes a "memory leak" (though strictly speaking it is none) when using
feh --reload on http URLs.

fixes valgrind warning about use of uninitialized values

This reverts commit 8b79bc33.

This fixes a segfault in --reload when the image becomes unloadable while feh
is running.

Note that this does not affect --reload with more than one file: If the
current image is removed, feh will simply jump to the next image. feh will
only quit if the file still exists, but can no longer be loaded.

feh_draw_info used to iterate line-wise over the info output, but now we need
to cache it somewhere to get the length of the longest line.

The info text used to be located 2px away from the bottom / left edges.  Now
that --draw-tinted has been implemented, that leaves us with an ugly edge, so
move it directly to the edge.

By default, feh draws white text with a black drop-shadow, which is well
readable in most, but not all cases.  The --draw-tinted option draws a
semi-transparent black box around all texts.  This improves readability, but
does not look as nice, so it won't become default behaviour.

It was suggested to use #7f7f7f7f for the background, but I decided that
for small images surrounded by a black border.

feh_draw_info used to unconditionally swallow the last character of a line,
assuming that it must be a newline. However, the very last line of a program's
output may not end in a newline, in which case its last output character was
omitted.