Remove outdated documentation.
Minor formatting fixes.
Added support for a "dry run" option that does not write anything to disk.
Added SetupLLVMIncludes in build files.
Fixed EnumModifiers to define proper power of two values.
Ignore TypeAliasTemplate declarations to get rid of some parser warnings.
Added some better logging for macro ignored declarations.
Removed duplicate preprocessed entity add in the new parser.
Explicitly construct the parser and keep it in ParserResult.

This fixes some non-deterministic behavior in the new parser but it means we are keeping around all the memory for parsing until the end of the process. This is a bit messy right now but at least we keep the API compatible between parsers. After all the new parser bugs are squashed, this will be reworked.
Do not check for duplicates when handling preprocessed entities.

Even though they share the same original ptr to clang's PreprocessedEntity, they can still have different locations so we need to duplicate them when converting the AST.