FIX (GitHub Organization app): add snapshot.bin generation and example file

- Add snapshot.bin generation example file `app/snapshot.js`
- Updated code to reflect changes
TESTING (node-webkit snapshots): test usage of node-webkit snapshot

- Add extra.bin generation example file `app/snapshot.js`
- Update code to reflect changes
- Add node-webkit-builder to gulp
- Add to .gitignore
STYLE (css): update text fields to reflect valid/invalid state

- Update text fields to reflect valid/invalid state. While invalid - border is red, valid border is green. Works on :focus only.
Revert "STYLE (css): update text fields to reflect valid/invalid state"

This reverts commit 6b95c707cc871fffa794dbf1a32c8331f57454ab.
Revert "TESTING (node-webkit snapshots): test usage of node-webkit snapshot"

This reverts commit 0a45204eda17eff0e6e17606af1ffdd163492a3c.
Revert "FIX (GitHub Organization app): add snapshot.bin generation and example file"

This reverts commit 6f43efeaa5b1fb7dc5c8c4b0d10e33c0c4c51671.
CLEANUP (tools): remove Gruntfile.js

- Remove Gruntfile.js and dependencies as we now use Gulp
TOOLS (gulp): add gulp build function

- add gulp build function, uses `node-webkit-builder`

NOTE: need to run `npm install` to install new dependencies
FEATURE (editor): add preview of markdown

- add preview of markdown files (files with .md extension)
STYLE (css): update text fields to reflect invalid state

- Update text fields to reflect invalid state. While invalid - border is red. Works on :focus only.
STYLE (css): add markdown css

- add css for markdown to match github css
STYLE (editor): add toggle to markdown in editor

- add toggle show/hide button to markdown files on toolbar of editor in shape of an :eyes:
Merge branch 'sasha'