Use JS markdown formatter

(cherry picked from commit 3941016)
add ICUNormalizer2CharFilter

Included ICUNormalizer2Charfilter in Lucene 4.8.0.
Add CharFilterFactory.

Now, char_filter name is "icu_normalizer", however token_filter name is same name.

Closes #27.

(cherry picked from commit 0cbf1b3)
Add integration tests

Closes #31.

(cherry picked from commit 39b83f0)
Update to elasticsearch 1.3.0

Closes #32.

(cherry picked from commit 4d17e47)
Update to Lucene 4.9.0

Closes #33.

(cherry picked from commit bc45a89)
Update to elasticsearch 1.4.0

Closes #34.

(cherry picked from commit ddd941b)
change version number for 2.3.0 release
Docs: make the welcome page more obvious

Closes #36.
Update to Lucene 4.10.0

Closes #33.
Fix missing line
Create branch es-1.4 for elasticsearch 1.4.0
Upgrade to Lucene 4.10.1 snapshot