Protect various attempts to get the name of a decl by making
sure it is a NamedDecl before trying.

Make sure we only consider a function to be a constructor
if it it is a member of a non-enum TagDecl.

Fix various 80-column issues and some engrish.


git-svn-id: https://root.cern.ch/svn/root/trunk@48423 27541ba8-7e3a-0410-8455-c3a389f83636