add .gitignore file and keep empty directory in Git

.gitignore

+.keep_in_git
+
+/build*
+
+source/RobotAPI/Test.h
+
+*.bak
+*#
+.#*
+*~
+
+.DS_Store
+CMakeFiles
+CMakeCache.txt
+
+*.o
+*.os
+*.a
+*.la
+*.lo
+*.so
+*.dylib
+moc_*
+

build/.gitkeep

+Git can only track files and not directory.
+
+Therefore this file is added to all empty directories
+which need to be available after a Git clone.