Add Guava dependency
Add inheritance map writing

New --write-inheritance/-H command-line option, iterates all classes
in mapping and writes inheritance (interfaces and superclasses) to file.

Example usage, generating inheritance map from MCPC+:

java -cp target/SpecialSource-1.3-SNAPSHOT-shaded.jar:mcpc-plus-1.4.7-R0.2-SNAPSHOT.jar net.md_5.specialsource.SpecialSource --srg-in ~/minecraft/1.4.x/jars/1.4.7/cb2obf.csrg --live --write-inheritance /tmp/h
Sort inheritance map written to file