Merge pull request #313 from lev-kuznetsov/master

Prioritize custom handler method handlers over default
Merge pull request #314 from lev-kuznetsov/master

Heatmap mocks
Merge pull request #315 from lev-kuznetsov/master

/heatmap/mock/data?format=json now returns a randomly generated dataset
Added newick format message converter; now request format=newick to get
stuff in newick format
Cleaner definition