Pers_debug - Remove 'prototype' comment

This parses as a warning when uploading releases to AMO
chrome.manifest - Add trailing slash to URI

This fixes a parse warning when uploading releases to AMO
Perspectives - Fix code for retrieving private browsing data

This interface changed in Fx20 and the old interface has now been discontinued.
Neatly, the old code will still work on Fx19 and earlier, and SeaMonkey.
Perspectives - Increase version compatibility for Firefox and Seamonkey
Unit tests - Add note on testing invalid certs
Perspectives - Increase version for 4.3.5 release!