opencga-renderer: some profiling.

with chunksize 1000:
60 ms: saving 1200 alignments in indexedDB.
80 ms: drawing coverage.
800 ms: drawing single reads.
Merge branch 'feature/alignment-and-variation' of https://github.com/opencb/jsorolla into feature/alignment-and-variation
opencga-manager: fixed bug about version retrieval.
removed debugger from histogram renderer.