make: Support the generator_filelist_paths input info.

Do like ninja and stop storing file lists in the source tree by putting
everything in the "out/gypfiles" directory by default. The directory depends
on the "output_dir" generator flag, and the --generator-output option can
make the files be stored into any location, including somewhere out of the
source tree.

BUG=chromium:297186, gyp:316
R=thakis@chromium.org,scottmg@chromium.org
Patch from Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>!



git-svn-id: http://gyp.googlecode.com/svn/trunk@1797 78cadc50-ecff-11dd-a971-7dbc132099af