adding submodules for tools/grit and third_party markupsafe, jinja2 and icu

- grit needed by build process
- icu lib dependency
- markupsafe and jinja2 needed to generate code from templates
adding submodule for fork of chromium/src/build project as
building wtf included with node

- adding node_chromium.gyp which depends on wtf
- adding gyp_node_chromium.py which is original gyp_node.py with minor
  additions in order to add settings and includes needed to build
  chromium libs
- adapting configure to use gyp_node_chromium.gyp
- adapting node.gyp to include node_chromium.gyp as a dependency
- this builds successfully on OSX with ninja using installed clang
  (instead of the custom one that comes with chromium)
adding mimimum required of WebKit to build wtf, based on commit: 3cc3842