import clang and clang-c headers from clang 3.5 stable

create basic module map for clang-c accessors
add bindings for numerous clang functions

adds references for
CompilationDatabase: complete
CompileCommands: complete
Index: still more todo
TranslationUnit: still more todo
Cursor: still more todo
SourceLocation: a bit more todo, but quite functional
SourceRange: a bit more todo, but quite functional
File: still more todo
Type: a bit more todo, but the majority of functional usage is present
and support extensions for CXString and CXError_code