Make layout URL mandatory

This will help us keep tracking of changes in layout, license
etc.
Remove unwanted escape for double quotes

 * Remove unwanted escape for double quotes from gu-inscript.js
 * Added test for gu-inscript
fix mapping of Oriya letters TTA and TTHA

In Oriya inscript layout, letters TTA and TTHA are incorrectly mapped to ` and ~.
Verified this with XKB.
Merge pull request #331 from kartikm/rules-URL-mandatory

Make layout URL mandatory
Fixed test for gu-inscript
Corrected test. Really.
Merge pull request #336 from kartikm/unwanted-escape-double-quotes

Remove unwanted escape for double quotes
Merge pull request #337 from jishnu7/master

fix mapping of Oriya letters TTA and TTHA