Add the ability to customize recompile settings

[shartte]

This also sets the default memory used for the recompiler to 1g.
I've ran tests, it also would run with 512m, but seems slightly faster with 1g (~10s).

These new options can also be used to run GC analysis on the javac process:

set ORG_GRADLE_PROJECT_neogradle.subsystems.recompiler.jvmArgs=-verbose:gc -Xlog:gc*,safepoint=info:file=C:\directory\gc.log:uptimemillis

(and then run garbagecat on it...)