fpGUI Debug Server now defaults executable name to 'dbugsrv'.

This means that if we use the dbugintf unit, that we could automatically
launch the debug server (if it is in the system PATH) if it is not
already running.
os/2 bitmaps with bitdepth of 1,4 or 8 have a 3 byte color palette.

I originally read it as a 4-byte color palette. This fixes the colors
of images (mostly), but there still seems to be some or other decoding
issues with larger than 65KB images.
code syntax consistency. Changes << to shl