version bump 1.7
EXP: resize multiple sizes at once
DEL: Deleted some debug lines
FIX: Do not resize if collage mode ON
  For multiple resize use resulting image instead.
BUGFIX: textboxes broken, fixed. Turns out all strings are considered
lists, so my validation was defective. added flag to function.
BUGFIX: If checkbox "resize" deselected after setting several sizes, artscript
ingored it.
Added experimental support for image watermark Centered.

Set "wmimsrc" value in settings to an absolute path.
	/home/user/image.xxx
like this
	wmimsrc="/home/user/image.xxx"
BUGFIX: If resize output is only one size and not multiple we will
not add a size suffix at the end
Fixes #3

Add image watermark support in GUI to turn on or off.
Settings have to be set in the config file.
BUGFIX: Image WM checkbox only available if image path is set
MINOR fix: checkbox ordering
ADDED. artscript2 test file
MINOR FIX: increase size of image frame to compensate margins
FIX: Possible permanent loop if convert unable to make thumbnail
FIX: Gimp caused infinite loop, path creation flawed was causing it
FIX: Added complete gimp conversion to get preview. It's slow
BUGFIX: Get canvas size by selecting the first layer on
multilayer xcf
BUGFIX: Don't call $program --version as it is very slow to load
look for files in path using wich.

TODO: look for binary paths using global $env variable
GUI reorganization and cleanup
GUI adjustments and organization
Validate function now accepts arguments to add files to main dict
This allows to call it for example to add files from events

Clean up and arrange of functions
Minor code reorganization
BUGFIX: Image watermark list only create a pair {name} {path} list
instead of creating 2 lists