#135 fix generated compile errors for nested and generic dataype params

[bergmanngabor]

The classes generated from this pattern now compile correctly:

pattern bar(e: java ^java.util.Map.Entry, u: java Integer) {
    e == eval(^java.util.Collections.singletonMap(1,2).entrySet.head);
    u == 4;
}

(And the query results are correct as well)

[bergmanngabor]

Fixes #135

[bergmanngabor]

Huge thanks for asking for more tests! You made the right call - the more extensive test coverage revealed that the solution was not quite perfect, since there were serious underlying classloading problems as well (some related, some unrelated to inner classes or generic classes). This lead me down a rabbit hole that culminated in the introduction of a caching mechanism to the Java project based classloader.

[bergmanngabor]

(Note that what I have introduced is resource-based caching, so one classloader per vql file. If you can tell me how to have one shared classloader per source project rather than resource, I am all ears. Even better: can related projects have related classloaders?)

[bergmanngabor]

Fixes #125 as well.