First crack at adding a GYP_GENERATOR for determining various things

This version reads a file to get a list of input files, then outputs
if any of the input files are contained as sources (or inputs to
actions/rules) in any targets.

R=mark@chromium.org

Patch by Scott Violet <sky@chromium.org>

Review URL: https://codereview.chromium.org/330053003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1936 78cadc50-ecff-11dd-a971-7dbc132099af
4 files changed