Clean up switchConversation
Merge pull request #437 from glamrock/master

new Opera extension and makefile
Fix weird bug introduced in #437
Fix Opera makefile
Switch current conversation styles to CSS class

Implement issue #436, move styles to CSS and trigger from code
by adding and removing classes (and setting the status attribute).

currentConversation, offline, and away are covered.
Merge pull request #438 from casebeer/declarative-styles

Switch current conversation styles to CSS class
Change the "block" function to "ignore" function

…to prevent selective sending of messages (this is a security fix,
related to issue #439)
Fix typo