Fix coding converntion violations: structs end on "_t".

Document typedef-to-class on a separate page per typedef (as in TMatrixD.html);
mention the existing typedefs for a class (extremely useful for 350 character templates).
TDocParser::Context() was returning the top of an empty stack when it was not parsing but only decorating keywords.
Fix a few issues found by the W3C validator: a stray </div>, methods' toggle/signal/... abbr was a shorttag and wasn't meant to be (obviously).
Also reference templated types.
Also reference typedefs in a different scope than the global scope.
Replace printf by a call to Info().
Bail out of a doc directive wants GUI but we cannot switch to non-batch.
Also allow scopes and templates as return types for the type eval of an expression like "a.b()->".


git-svn-id: http://root.cern.ch/svn/root/trunk@23908 27541ba8-7e3a-0410-8455-c3a389f83636