List of photos (gallery.list)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
One photo per line, tab-separated columns:

	File name (relative to OrigDir in config)
	Identifier (16 hex digits)
	Orientation: one of "l", "r", "d", "."
	Transformation -- sequence of:
		n	normalize contrast
		s	sharpen
		h	equalize histogram
	Title (UTF-8 string)

Lines starting with "#" are ignored.


Photo meta-data (PhotoDir/gallery.meta or CacheDir/cache.meta)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Perl Storable containing a single hash.

$meta->{photo}->{$identifier} is a hash of:
	o		orientation
	xf		transformation applied
	w		width after scaling
	h		height after scaling
	title		photo title

$meta->{sequence} is an array of photo IDs as they appear in the gallery.

[CacheDir only]
$meta->{thumb}->{$format}->{$identifier} is a hash of:
	w		thumbnail width
	h		thumbnail height