* Make LIB_TABLE_BASE::GetCount() return unsigned. This is more
consistent with the behaviour of STL containers (especially the
boost::ptr_vector this is really accessing). Sadly
wxGridTableBase() forces an int, so a cast is still required
at the WX interface.
* Make LIB_TABLE_BASE::At() return a reference. First, this is more
consistent with normal STL indexing operator[]'s, and secondly, it
allows an idiomatic const index method (so you can access const
LIB_TABLE_ROWs from a const LIB_TABLE_BASE).
The motivation is to allow use of this class and LIB_TABLE_ROW
in a test program, where the LIB_TABLE_BASE is const.
0c6ec7dbb3