lib: intro the method String::file_copy_to

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: keep a list of source files to copy to the compile_dir

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: actually copy over files to compile_dir

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: move adding gc_chooser out of the makefile generation

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: copy over gc_choser files

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: use only local files in compilation

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>