Merge pull request #320 from gdusbabek/fix_validate_points_params

Throw 400 instead of 500 when 'points' doesn't parse.
Merge pull request #322 from gdusbabek/ingest_empty_bundle_fix

Return 400 when there are no valid metrics.
Merge pull request #321 from gdusbabek/validate_ttl

Validate collectionTime and TTL.
Make locator fetch concurrency configurable

Capping the number of locators fetchers results in a cap in the number
of rollups a single BF process is able to do. Doing more requires
another JVM process, which can get expensive.
Define config var earlier

Need to define the config var earlier so it can be used
when configuring LocatorFetchThreadPool
Merge pull request #323 from dlobue/configurable_locator_fetch_concurrency

Make locator fetch concurrency configurable
Merge branch 'master' into rax-stage