Many of the tests were not running, or did not check the exceptions.
I renamed all tests to meet *Tests* so they run, and assert exception messages.
Also because we must (currently) invoke tika with additional privileges, I added
the security logic, and fixed unit testing to call our static method directly.
This must be package private for security reasons, i simply put everything in
org.elasticsearch.mapper.attachments package.
I upgraded tika to the latest, so we are up to date, and removed logic around
tika == null and old locale issues.
To simplify plugins maintenance and provide more value in the future, we are starting to build an `elasticsearch-parent` project.
This commit is the first step for this plugin to depend on this new `pom` maven project.