Keyboard shortcut injection throwing errors

[neocotic]

It seems that sometimes the errors are being thrown when injecting the shortcuts.js script in to open tabs caused by undeclared permissions in the manifest. So far I believe this only happens for special pages (e.g. chrome_://_) as these permissions cannot be requested for these but could potentially be for others.

A possible solution involves wrapping each injection with a try/catch block and/or checking for special pages.

[neocotic]

This has been fixed to an extent but chrome will throw errors when attempting to inject these scripts as protected pages load. However, these errors should have no damaging effect to the extension.