Implement #525
Merge pull request #526 from emmanuel-keller/1.5

Implement #525
[maven-release-plugin] prepare release v1.5.2
[maven-release-plugin] prepare for next development iteration
- Fix UTF-8 issues in Debian package.
- ActiveDirectory login get group members recursively
Merge pull request #535 from emmanuel-keller/1.5

- Fix UTF-8 issues in Debian package.
Fix wrong error log when using the external parser
Merge pull request #543 from emmanuel-keller/1.5

Fix wrong error log when using the external parser
MoreLikeThis implementation
Merge pull request #544 from emmanuel-keller/1.5

MoreLikeThis implementation
Fix MoreLikeThis WebService pattern
Fix MoreLikeThis WebService pattern
Merge pull request #548 from emmanuel-keller/1.5

1.5
MoreLikeThis query sorted in score descending order.
Merge pull request #552 from emmanuel-keller/1.5

MoreLikeThis query sorted in score descending order.
MoreLikeThis API returns query string
Merge pull request #555 from emmanuel-keller/1.5

MoreLikeThis API returns query string
Error message on invalid OPENSEARCHSERVER_DATA environment variable
Merge pull request #558 from emmanuel-keller/1.5

Error message on invalid OPENSEARCHSERVER_DATA environment variable
Implements issue #561