Widgets implements the MochiKit's DOM coercion protocol
Widgets don't require an element parameter in the constructor, they will make
a default one if the element to wrap is not provided. Note that the default
element will not be appended to the document automatically.
UI.Table: rowAdded signal is emited with the row index as an extra second
parameter.
Fixed UI.Table.prototype.selectRow() when passing -1 as argument.
CSS friendly Table rendering:
+ Added col_0, col_1,...col_n classes to rendered <th>s.
+ Added row_0, row_1,...row_n and even or add classes to rendered <tr>s.