Partner Find screen: fix for *extremly* slow screen when the returned search result was into thousands of rows.

The solution consists of the following:
* The Auto-Size calculation on the Grid data is now only done on the first 'page of data' that is returned, and not on all rows. That is sufficient and fast.
* Due to the necessary changes I ran into problems when the Grid was populated with subsequent searches. Since we had somewhat related problems in the years past I simply changed the implementation - now a new Grid is created for every search operation.
* Also, if the user switches between 'Detailed results' and non-detailed the AutoSizing is no longer called, which was unnecessary and could take a very long time on a large number of Grid Rows.
Problem seen on Partner Find screen: an unhandled exception occured when pasting a string into Partner Key field when that string wasn't a number that fitted an Int64 but was some other 'random' string that was in the Clipboard at the time of pasting.
Partner Find screen: now that the GUI is responsive after the fix in the previous commit, OpenPetra can handle the pressing of the 'Stop' button. However, the implementation of cancelling the DB query and the processing on the server-side was majorly flawed! I took over the implementation from Petra 2.3, which works.
Improve various UI updates related to searches.
Comment Logging statements.
Commented more logging statements...
merge from Branch 'lp:~christian-k/openpetraorg/dev_20131129_PartnerFind_Fixes'.