Issue 78: Added javadoc to some Randomizer methods.
Issue 78: Added javadoc to some Randomizer methods.

tgvaughan/beast2,tgvaughan/beast2,CompEvol/beast2,Anaphory/beast2,CompEvol/beast2,tgvaughan/beast2,Anaphory/beast2,Anaphory/beast2,CompEvol/beast2,tgvaughan/beast2,Anaphory/beast2,CompEvol/beast2