rename Callback to Delegate

rename Callback to Delegate

2008-01-12  Juerg Billeter  <j@bitron.ch>

	* vala/Makefile.am, vala/parser.y, vala/vala.h,
	  vala/valaattributeprocessor.vala, vala/valacodecontext.vala,
	  vala/valacodegenerator.vala, vala/valacodevisitor.vala,
	  vala/valadatatype.vala, vala/valadelegate.vala,
	  vala/valadelegatetype.vala, vala/valainterfacewriter.vala,
	  vala/valanamespace.vala, vala/valanulltype.vala,
	  vala/valasemanticanalyzer.vala, vala/valasignal.vala,
	  vala/valasymbolresolver.vala, gobject/valaccodegenerator.vala,
	  gobject/valaccodegeneratorinvocationexpression.vala,
	  vapigen/valagidlparser.vala: rename Callback to Delegate

svn path=/trunk/; revision=836