Add gyp_nacl.py to make gyp_nacl importable on python 2.6
Add gyp_nacl.py to make gyp_nacl importable on python 2.6

Modeled after gyp_chromium.py in the Chromium repo.
R=binji@chromium.org
BUG=red NaCl SDK bot

Review URL: https://codereview.chromium.org/50003003

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@12324 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client