Added page title + improvements

The title shows the tags taht are being browsed, on index, it shows a
slash.
Improved incremental loading and added support for tag searching.
Added support for tag browsing (in popup, select and click search; somehow
the ItemClick event is not firing -- to support single tag navigation).
Added BackButton.
Fixed a bug in Globals, do not try to put a key in a dictionary if the
same key already exist.
Correctly set tag url parameter separator.
Corrected style for page title.