Autotools: Updated build environment to include ico.rc when building for Windows.

The dependencies for ico.rc have to be manually included in the makefile.
Currently, it depends on version.h and 7k.ico
version.h: No longer included by ALL.h, now directly included when files need it (AM.cpp and ico.rc)
OBLOB.cpp: Fixed a crash in DEBUG mode when Blob tries to mem_del(NULL)
OERROR: Fixed an issue with atexit crash after Error::run is called. The function failed to set sys.signal_exit_flag to signal application termination
Game menu: The Load menu now works properly again ingame. Fixes a bug introduced in 44cc7c71041.

The Sys::load_game function sets signal_exit_flag, but this caused the load menu to immediately
close again.
VgaSDL: Decrease minimum time between frames to 17 ms, capping at just under 59 FPS
Merge branch 'patches-17-1-2014' of https://github.com/MicroVirus/7kaa into merging