Refarctored XML-RPC code for better handling errors and showing status in the GUI.

-Refactored XMLRPCCallTask to return the exception if one was cought.
-Updated XMLRPCChannelManager to work with the new code, but not show status in the gui.
-Updated XMLRPCTorrentManager to work with the new code and tell it's status to the GUI through ISearchListener.
-Updated XMLRPCDownloadManager to work with the new code, but not show status.
Improved strings and put them into strings.xml. Also improved the flow of the messages.
Merge branch 'master' into startScreen

Conflicts:
	tsap/res/values/strings.xml
	tsap/src/org/tribler/tsap/downloads/DownloadActivity.java
	tsap/src/org/tribler/tsap/thumbgrid/ThumbGridFragment.java
Merge pull request #67 from wtud/startScreen

When the user has returned from the settings fragment the screen keeps displaying the message "Loading results...". This will probably be fixed in issue 97 so this code is merged anyway.