Git revision is generating on build time (not on configure time). In case of uncommited changes this revision will be marked as "dirty". If cmake cannot retrieve revision from git history (i.e. from packaged source code), cmake will attempt to read "git-hash.txt" from `PROJECT_SOURCE_DIR` (it will be generated on build time; after implementing packaging workflow it can be reworked).
Reworked main screen and console output to display proper version.
Version project now is 1.5.0 as previous PATCH value (500) was intended to be D3_RELEASE_BUILD_NO, autogenerated on compile time. As we switched to GIT_HASH, D3_RELEASE_BUILD_NO now useless.
Generated d3-linux.hog now places next to Descent3 executable, ready to play. Scripts also generated in ${CMAKE_BINARY_DIR} and don't pollutes source dir.
