Web application support (targeted for FxOS)
- The required app manifest
- SVG Logo provided by Scrollback
- Logos reworked for various resolutions
- No script to prompt installation, no MIME-type fix

Signed-off-by: Soumya Deb <debloper@gmail.com>
Changed developer URL according to @aravindet's suggestion
Merge pull request #434 from debloper/master

Web application support (targeted for FxOS), closes #244