Stabilization of the tool

[Toparvion]

After first heavy release of jMint (v1.1) a lot of non-obvious effects were discovered while applying the tool in various use cases. The effects must be researched and classified either as bugs to fix (with corresponding issues) or as features to know (with corresponding notes in documentation).
Here's non-exhaustive and non-final TODO and check list:

• learn everything about application class loaders access from within Java Runtime classes;
• check the tool's compatibility with interface methods modification;
• remove explicit return type recognition (as it interferes with BEFORE cutpoint code when applied to methods with non-void return type);
• choose the optimal solution for Play1 application class loader compatibility;
• prevent premature SLF4J initializing (or even migrate to another logging facade) to make jMint compatible with fat-jar-based applications like Spring Boot ones.