sketch of an expression parser with own fuzzy AST

Add a function fuzzyparse() which parses binary operators in expressions
according to their precedence.

The AST behind this is a copy of the clang AST with similar names and
interface, but stripped of all unnecessary functionality and optimizations,
therefore much simpler to generate and use.
temporarily disable tooling for faster compilation
Add unary operators (currently only for dereferencing)

Also moved the AST into the namespace clang::fuzzy instead of clang::highlight.