Incorrect row deselection behavior in PagingScrollTable

[GoogleCodeExporter]

Problem 1 steps to reproduce:  
1. Set a ONE_ROW Selection Policy in a PagingScrollTable
2. Click to select a row and row gets selected and RowSelectionEvent is fired
3. Click on a row again and the row is selected and RowSelectionEvent is
not fired

What is the expected output? 
The normal expected behavior is that the first click selects a row and the
second click deselects it.  This behavior is common to spreadsheet type
formats.

Problem 2 steps to reproduce:
1. Set a MULTI_ROW Selection Policy in a PagingScrollTable
2. While holding down the shift key, click on row 1, 2, 3.  All 3 rows are
now selected
3.  Now click again on row 1 (while still holding down shift key).  Rows 2,
3 get deselected and row 1 stays selected

What is the expected output?
The normal expected behavior is for row 1 to be deselected and to rows 2
and 3 to stay selected to allow user to keep the set of rows they have
already selected while deselecting a specific row.  This behavior is common
to spreadsheet type formats.

Original issue reported on code.google.com by alfamark...@gmail.com on 10 Feb 2010 at 5:39