Eager norms loading options.

Norms can be eagerly loaded on a per-field basis by setting norms.loading to
`eager` instead of the default `lazy`:

```
"my_string_field" : {
  "type": "string",
  "norms": {
    "loading": "eager"
  }
}
```

In case this behavior should be applied to all fields, it is possible to change
the default value by setting `index.norms.loading` to `eager`.

Close #4079
Left-arounds from previous commit.
s/StringBuffer/StringBuilder
Clarify options for flush request
Use a tolerance to decide if a value is less than the threshold

Adding a small value to the threshold prevents weight deltas that are
very very close to the threshold to not trigger relocations. These
deltas can be rounding errors that lead to unnecessary relocations. In
practice this might only happen under very rare circumstances.
In general it's a good idea for the shard allocator to be a bit
more conversavtive in terms of rebalancing since in general relocation
costs are pretty high.

Closes #4630
Add a message about import style

We don't have a consistent style and we don't want new contributors to
get hung up on trying to figure out the style.
Update Eclipse template to use the new license header.
Fixed match assertion that didn't run any assert with object of different types that don't extend Number
[TEST] remove yaml tests for 1.0 from 0.90 branch
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