convert: conversion of datfile terrain sections to new structure definition
convert: implemented zero data verification and fixed some bugs
convert: removed section selection for dat file
convert: set skipped members to empty values instead of forgetting them

the read continue member behaves correctly, but the members
have to be existant and empty instead of missing.
convert: empires2_x1_p1.dat is read completely with new export infrastructure

c files are generated as well.
convert: introduced basic dat file read caching
convert: new name for the terrain specification file
convert: created compression wrapper for the empires dat file
convert: forbid using c++ bool type
convert: shorter and redundancy-free filenames for the data tree
convert: better debug output and a forward declaration creation stub
convert: add missing typerefs for multisubtype member
convert: suppress non-used argument warning when struct has no members
convert: export language dll ids for units
engine: introduced working directory handling class
convert/pefile: fixed wrong resource leaf data offset
convert: prettier debug output for pefile reading
convert/pefile: allow zero-padding after a string table
convert: renamed sound_item member for sounds