Add visualizers for more clang types. Create more C++-like visualizations for existing Clang types

Created visualizer for PointerType, LValueReferenceType, RValueReferenceType, and TemplateParmType.
In addition, cleaned up the display of existing types to be more C++-like. For example, instead of

  SubstTemplateTypeParmType: {Identifier (("T"))} => Record (25), {Identifier (("A"))}

it now displays more readably as 

  SubstTemplateTypeParmType: {typename T <= struct A}

The <expand> sections still can be used for all the gory details if necessary.

llvm-svn: 263638