Suspend Background Tabs

This is Wladimir Palant's original extention, which used to be on the AMO, but it was suddenly removed. I simply unpacked the XPI and made sure it was working an uploaded it to GitHub, and am now trying to improve it.

Task list

• Change add-on structure for no good reason.
• Add comprhensive blacklist features. (Such as perscript name, not just by site.)
• Add suspension of Flash objects.

Licence: See LICENCE file.