Add more logging to recent aggregations failures.
Made hole character in XAnalyzingSuggester part of Postingsformat

* Hole charactor now can change with new releases
* Fixed bug where the SEP_LABEL constant was used instead of the sepLabel instance variable
* Replaced if- with switch-statement
Use FilterDirectory from lucene instead of maintaining a copy

FilterDirectory has been ported to Lucene in LUCENE-5204 which makes
the class in elasticsearch obsolet. This commit removes the class and
moves the static utils that are not in lucene to `DirectoryUtils`
Upgrade Maven Assembly Plugin to 2.4

Closes #4278.
Upgrade Maven Compiler Plugin to 3.1

Closes #4279.
Upgrade Maven Dependency Plugin to 2.8

Closes #4274.
Upgrade Maven Eclipse Plugin to 2.9

Closes #4277.
Upgrade Maven Jar Plugin to 2.4

Closes #4281.
Upgrade Maven Resources Plugin to 2.6

Closes #4280.
Upgrade RPM Maven Plugin to 2.1-alpha-3

Closes #4282.
Upgrade Maven Source Plugin to 2.2.1

Closes #4276.
Upgrade Maven Surefire Plugin to 2.16

Closes #4275.
Fixed positive infinity bug that can occur in specific scenarios when score mode average is used.

Closes #4291
Randomly use a cached filter.
Wrap the ChildrenQuery in a XFilteredQuery to also execute other code paths (scorer#advance)
Added aggregation support to the percolate api.
Closes #4245
OOM when building with java6

The maven-compiler-plugin upgrade from 2.3.2 to 3.1 (see #4279) could cause out of memory issue when building the project with Maven and JDK6 and default memory settings (no `MAVEN_OPTS`).

This issue does not appear with JDK7.