don't schedule a flush if there are no operations in the translog
this can happen with the 30m time base setting expires
randomize flush interval so multiple shards won't flush at the sam time
- also, allow to update interval using update settings on an index
Fix typo

reported in https://github.com/elasticsearch/docs/issues/3
Use FHV's phraseLimit

This prevents poisoning the FVH with documents that contain TONS of matches
which take tons of memory and time to highlight.

Closes #4645
Stop FVH from throwing away some query boosts

The FVH was throwing away some boosts on queries stopping a number of
ways to boost phrase matches to the top of the list of fragments from
working.

The plain highlighter also doesn't work for this but that is because it
doesn't support the concept of the same term having a different score at
different positions.

Also update documentation claiming that FHV is nicer for weighing terms
found by query combinations.

Closes #4351
Fix compilation under javac 1.6.
move ack tests for cluster update settings to its own test with scope test, and all other ack tests to scope suite for faster execution
add support for tera and peta units

fixes #4640
closes #4641
when specifying size 0, just use the total hits collector in query phase
no need the (old) hack of setting the size to 1 anymore really...
Create standard gc and memory_pool names for Jvm stats
fixes #4661
use proper logging
add joda-convert so missing annotations in joda-time will not cause failures when used as dependency
fixes #4660
Add warning phrase suggester's max_errors

large number can badly impact performance.
Expose headers list in RestRequest

Closes #4609
move RestRequest to be an abstract class, and expose local/remote address
[DOCS] Fixed duplicate ID in highlighting
Add more traces in case of failure when testing with actual plugins
remove default `_all` for `type` and `index` if these are missing in REST tests

If a type or path is missing in the REST test yaml file, it is
automatically replaced with _all. This makes it hard to test changes
in the api, for example adding the possibility to leave the index
blank in addition to _all and * in the uri.

closes #4657
[DOCS] Added documentation for SameShardAllocationDecider

Closes #4615
give the compiler more memory, otherwise it fails sometimes