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
BUGFIX: Protect files with white space when inserting to main tree
GUI: Watermark Style elements added
ADD: scroll trough tabs in notebook
FIX: Canvas should react only to left button
Now the user can edit the input file list.
Add: use the button at the top
Delete: select the entries you wish to remove.

This is very usefull to select all from a directory and delete the
entries you dont want/need
Added code comments
Rename extension header to "ext"
Add TODO items
ADD: WAtermark text combobox can be edited using right click
GUI: added scale widgets for opacity
FIX: Error when file generates a thumbnail. for jpg png original item
value deleted.