convert: padding blendomatic tile filenames enabled
convert: extracted tile generation function for bitmask reusage

the function for drawing isometric tiles can be used for
drawing the bit masks and the alpha masks. therefore i had to extract it
convert: fixed data ranges for bit and 7bit masks

the alpha masks do not use 255 bit alpha values, they use 127..
convert: added PE file reader

capable of:
reading arbitrary sections
reading of ressource trees
reading of string ressources, by id and language

restrictions:
tested only for age2_x1 german language.dll
not yet integrated into rest of convert infrastructure
Merge branch 'master' of git.sft.mx:openage