Add .DS_Store to gitignore
Add support for built applications in build script

A new sibling directory to apps/ - built-apps/ - is introduced to contain already built applications to be copied to apps/ during the build process.
All applications in built-apps/ are neither npm installed or mopped because they are ready to be deployed.

This provide us enough flexibility to have applications with slight changes to their original source code or dependencies.
Add built application photoFX

This application has Q with stacktrace support disabled.

Origin: https://github.com/montagejs/photofx/commit/7db3eed36b1b793f92fd202fd9c39c09ecc88d0c
Add built application carconfigurator

This application has Q with stacktrace support disabled.

Origin: https://github.com/montagejs/carconfigurator/commit/b51ff4d98586220a484a28d1d92ac8c6f29bac28
Add built application paparazzi

This application has Q with stacktrace support disabled.

Origin: https://github.com/montagejs/paparazzi/commit/c7cc89ee49c0d71f0e6a9ed2ac1b329399252822
Add built application calculator

This application has Q with stacktrace support disabled.

Origin: https://github.com/montagejs/calculator/commit/52cba8c2daa116431690eabd26bfd9e042aaaa13
Add built application temp-converter

This application has Q with stacktrace support disabled.

Origin: https://github.com/montagejs/temp-converter/commit/41ef4a3d2eaf4d80bc955b1f9f2702ffaa2b5185
Merge branch built-apps
Correct app links
Remove social buttons from api docs