Initial implementation of custom _all field

Closes #4520
Added setup task that clears the test template before running exists_* tests
River does not start when using config/templates files

From elasticsearch 0.90.6, when you have templates files defined in `config/templates` dir, rivers don't start anymore.

Steps to reproduce:

Create `config/templates/default.json`:

```javascript
{
  default:
  {
    "template" : "*",
    "mappings" : {
      "_default_" : {
      }
    }
  }
}
```

Start a dummy river:

```sh
curl -XPUT 'localhost:9200/_river/my_river/_meta' -d '{ "type" : "dummy" }'
```

It gives:

```
[2014-01-01 22:08:38,151][INFO ][cluster.metadata         ] [Forge] [_river] creating index, cause [auto(index api)], shards [1]/[1], mappings [_default_]
[2014-01-01 22:08:38,239][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:38,245][INFO ][cluster.metadata         ] [Forge] [_river] update_mapping [my_river] (dynamic)
[2014-01-01 22:08:38,250][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:39,244][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:39,252][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:40,246][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:40,254][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:41,246][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:41,255][INFO ][river.routing            ] [Forge] no river _meta document found, retrying in 1000 ms
[2014-01-01 22:08:42,249][WARN ][river.routing            ] [Forge] no river _meta document found after 5 attempts
[2014-01-01 22:08:42,257][WARN ][river.routing            ] [Forge] no river _meta document found after 5 attempts
```

With elasticsearch 0.90.2 or with no template file in `config/templates` dir, it gives:

```
[2014-01-01 22:22:32,096][INFO ][cluster.metadata         ] [Forge] [_river] creating index, cause [auto(index api)], shards [1]/[1], mappings []
[2014-01-01 22:22:32,221][INFO ][cluster.metadata         ] [Forge] [_river] update_mapping [my_river] (dynamic)
[2014-01-01 22:22:32,228][INFO ][river.dummy              ] [Forge] [dummy][my_river] create
[2014-01-01 22:22:32,228][INFO ][river.dummy              ] [Forge] [dummy][my_river] start
[2014-01-01 22:22:32,234][INFO ][cluster.metadata         ] [Forge] [_river] update_mapping [my_river] (dynamic)
```

Closes #4577.
Closes #4656.
Ignore empty config paths
[SPECS] Updated percolator specs.
[TESTS] Added percolator rest tests.
[SPEC] Fix cardinality of the repository parameter in get snapshot action
Fixed typo
Removed redundant statements.
add internal force local flag, used by tribe node
tribe node to set it to true so all master read operations will automatically execute on the local tribe node
Only refresh id_cache if the parent field is active.
[SPEC,TEST,FIX] add spec and tests for termvector api and fix inconsistencies

- index and type were not read from the uri with the _mtermvectors api
- ids were not read from the uri parameters with the _mtermvectors api
Deprecated use of partial fields in Java API, was already deprecated in the docs for the search API

Closes #4118