Merge pull request #20 from DaveAckley/master

First cut cheapo 'window system' implementation..
GridPanel handles click tile selection
StatisticsPanel renders correctly
Eliminate virtual method from Atom and dependents; improve doc to explain why.
Include .dox files as documentation; define \lgpl special command
Some initial mainpage doxygen to get us started
Add the GPL somewhere since the LGPL depends on it.
Make a COMPILATION_REQUIREMENT template hack to fail compilation if a template expression is false; use it in Atom to ensure sizeof(Atom)==sizeof(m_bits)
Doc tweaks; ws.
Put core/Util names in MFM namespace as now advertised.
Merge with trunk
Exclude doc/internal