Sort filelist by dirname, then by name. This results in file entries
sorting before subdirectory entries.

Useful in conjunction with upcoming prev_dir and next_dir navigation
actions.

We did not preload when SORT_MTIME, so check opt.sort > SORT_MTIME
before offering to sort by file size.

The CB_* enum block was run through s/, /,\n\t/g for legibility.

previously, a button/key definition with an invalid action name would assign
the specified key to the most recent valid action. E.g. "zoom_in 4\ninvalid 5"
wuold assign button 5 to zoom_in.

The if statements are needed because we cannot pass a NULL pointer to
XFree.

Purpose of "--no-recursive" option is disabling effect of "--recursive" option that enabled by user's theme.

* Added an --insecure option to disable host/peer verification in libcurl.
This allows feh to load images on HTTPS hosts with self-signed certificates.
For security, this is not the default.

* Fixed an include in show_usage.

this fixes a segfault when combining --scale-down and --thumbnails on a
sufficiently large directory

this actually uses the old "force geometry" workaround to get the
scale down behaviour (which makes the code a lot cleaner) by
first setting the geometry after the window is created (to avoid
creating a 0x0 sized window, which X does not like).

also mark images as removed/processed when clicking on them in thumbnail mode and --action is specifed

The following adds the ability, when using `feh` as a background setter,
to use a specific Xinerama screen to render a provided image. Along with
the provided '--bg-*' option, the '--xinerama-index' argument will be
used to identify the index of the detected Xinerama screen to use.

Signed-off-by: James Knight <james.d.knight@live.com>

The 'fehbg' variable can be allocated whether or not the user wishes to
generated a fehbg file. Ensure the variable is free'ed before we return.

Signed-off-by: James Knight <james.d.knight@live.com>