Mark DataType as abstract base class

Mark DataType as abstract base class

2008-03-05  Juerg Billeter  <j@bitron.ch>

	* vala/valaclasstype.vala, vala/valadatatype.vala,
	  vala/valainterfacetype.vala, vala/valainvalidtype.vala,
	  vala/valatypeparametertype.vala, vala/valavaluetype.vala,
	  vala/valavoidtype.vala, gobject/valaccodegenerator.vala,
	  gobject/valaccodegeneratorinvocationexpression.vala,
	  gobject/valaccodegeneratormemberaccess.vala,
	  gobject/valadbusbindingprovider.vala:

	  Mark DataType as abstract base class

svn path=/trunk/; revision=1104