gdi/picexif: Remove unused variable "data_precision"
gpixmap: Copy palette to hardware only once.

Keep track of physical RGB table, and convert it only once. This
assumes that no one adapts the palette after having rendered it.

This prevents having to process up 1k of data for each hardware
blit.
gdi/epng, gdi/gpixmap: A few minor optimizations, use argb()

Move "if" outside loop.
Use the cheap argb() function instead of re-doing it the hard way.
Add box-specific display support, in particular vuduo2

When a skin_display_(boxtype).xml exists, use that instead of the
default one. Create a bit of a vfd skin for the vuduo2 (which has
a 140x32 sized vfd).

Could be replaced with a "displayname" configure parameter, so
that a display skin is chosen based on machine features. Then the
--with-textlcd and similar options can be dropped.
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2