Fix linux runtime dependency installation

Fix for adobe/brackets#4270

* Copies chromium install scripts to symlink `libnss3` and `libnspr4` locally into `/opt/brackets/` then set `LD_LIBRARY_PATH` to use the symlinked libraries
* Creates a new `brackets` wrapper script that is copied to the staging folder `pacakge-root/opt/bracekts`
* Creates a new symlink `/usr/bin/brackets` to point to `/opt/brackets/brackets`
* Update dependencies to match `google-chrome` 28