Valama: Improve build system integration over UI

 * Implement clean and distclean for cmake build system.
 * Add remove_recursively method (rm -rf).
 * Menu changes:
     * Project menu
        - Settings
     * Build menu:
        - Build: make
        - Rebuild: make clean && make
        - Clean build: make distclean && make
        - Clean: make clean
        - Clean all: make distclean
     * Run menu:
        - Execute
        - Stop