Fix issue #235

Without an "Accept" request header, we get error 403 with the Wordpress plugin Bad Behavior
Precaution to handle issue #238
Improved UnifiedDisplayView
Change to PXListView
Limit annoyance when refresh occurs in Unified layout
Updated PXListView (cosmetic changes)
Updated UnifiedDisplayVIew

Fix progress indicator
Performance optimization of -(PXListViewCell*)listView:(PXListView*)aListView cellForRow:(NSUInteger)row
Limit as much as possible forced display refreshes
Reviewed and simplified treatment of problematic cases
Avoid call to private methods of PXListView
Use notification to detect that the web view has loaded

Instead of waiting calls to webView:didFinishLoadForFrame: as a frameLoadDelegate, we register for notifications of WebViewProgressFinishedNotification.

webView:didFinishLoadForFrame: seems to be called early on OS X, even when ensuring the frame parameter is the main frame: <http://stackoverflow.com/questions/12120772/how-to-know-when-a-webview-has-finished-rendering>
Fix getting id's of starred articles

Fix needed by Inoreader.com
Added InoReader to list of known open reader servers.
Prioritize RSS / Atom types in "Accept" HTTP headers

Seems to solve http://www.cocoaforge.com/viewtopic.php?f=18&t=26440
Fix issue #234 (vertical layout problem with cells having a single line)

Partially reverse commits 28c95fe21d and f6b5346727
Updated Growl to 2.0.1 version
Updated some copyright info and dates
Browser : handle scripts' requests to open a new window
Fix progress indicator in Unified display view
Merge pull request #244 from barijaona/bugfixes

Multiple tweaks
Upgrade version number to 3.0.0 Beta 20
German

Translation and Update of language
Merge pull request #249 from biphuhn/master

German