Handle absolute paths for BINDIR in CMakeLists.txt

Looks like this was accidently removed when splitting the CMake file
between engine and game data.
Merge pull request #907 from dorkster/cmake

Handle absolute paths for BINDIR in CMakeLists.txt
Load only last hero_options.
Merge pull request #909 from igorko/fixes

Load only last hero_options.
Merge remote-tracking branch 'remotes/upstream/master' into render_refactor