Added functional interface types (Java)

This should fix https://github.com/CraftTweaker/CraftTweaker/issues/999

Changes how Classes from Stdlibs are found in the NativeModule so that their Java type parameters properly match the ones from the Stdlibs files

Mwahaha, Jared you will have to review this :manic_laugther:

.. Unless they have 'nope' in their name

Functional interface wrappers should work now
Implementing a method with a signature differing from the actual one (e.g. when dealing with generics) now creates a proper bridge method
The Java Bytecde compiler used an incorrect method in checkCast
We now no longer use hardcoded 'accept's as method names but whatever the context tells us to.

Currently only supports 'accepts' methods, until we can get a way to get the actual method signature/name from the class

- Fixed a number of bugs
- Upgrading build system to a more uniform system
- Improving error output (for IDE)
- Changed parser to generate line offsets differently (easier for IDE to process)

- Save collapse state of the project browser tree

- Added support for INTERFACE calls in java source code generation
- Minor source code generation quality improvements

- Added support to have a native method both as operator and named method

- Fix float suffixes on integers

- Fix getters for globals not having their corresponding fields registered correctly in the native implementation
- Added java sources for JavaScripting

- Fix default constructor not working properly
- Fix integration classes without exposed constructor being instantiable if they have a default (non-exposed) constructor
- Fix extern methods failing validation

- Fixed constructor support for native classes
- Added project for maven build
- Added missing StdLibs.zip

- Simplified compilation process somewhat; removed CompilationUnit class and work more module-oriented instead

- Slightly improved the way modules are compiled