Remove installer dependency on ClassPathCrawler

The installer has a dependency on ClassPathCrawler via RulesEngineImpl and PathResolver (used by UninstallerDataWriter).
This should not be required as:

• all classnames emitted by the compiler should be fully qualified or readily mapped to an internal IzPack class
• ClassPathCrawler can return incorrect classes if they happen to have the same simple name
• ClassPathCrawler is not particularly efficient as it has to scan the entire class path

The RulesEngineImpl dependency on ClassPathCrawler should be removed.
The compiler specific parts of PathResolver should be moved into a new class (e.g. CompilerPathResolver) residing in the izpack-compiler module.