Added support for ESC-O escape sequences in addition to ESC-[.

Process_Key doesn't query termcap or terminfo for the correct
control sequences. Accepting both ESC-[ and ESC-O mimics xterm.
Systems that define unsigned int but not DEF_UINT can now build w/o warnings.
Moved DEF_UINT for Haiku to reb-config.h
Reverted to previous systems.r file.
Merge pull request #154 from Tectorum/master

Fixes warnings when building & terminal support under Haiku