paths.c and did a general namespace cleanup:
s/PATHP/Path*/  s/PATHIMAGELISTP/PathList/ and friends.

Paths are now copied on image duplicate (fixes bug #5726).

Removed Path Tool and XInput Airbrush from the build and
renamed "Layers & Channels" to "Layers, Channels & Paths".

Applied patch from Wolfgang Hofer to xjt.c that enables loading
and saving of paths based on Andy's change explained below.


--Sven