DATAMONGO-937 - Add support for creating text index.

We now support creating text index based on information gathered on domain types.

Using @TextIndexed marks properties to be considered for the full text index. Use the weight attribute to influence document scoring during search operations.

Please note that using @TextIndexed on entity properties forces all properties of any sub document to be considered as part of the text index. Any set weight will in that case be propagated to the siblings taking the most recent weight information into account, which means that a the weight attribute can be overridden for properties in sub documents.

The setting the index default language can be done via @Document(language) while @Language can be used to define the language_override field.

As text search is disabled by default for mongodb 2.4 we use a jUnit ClassRule to restrict integration tests potentially creating text index (as the entities for testing are found in the classpath) to only be executed in when a 2.6+ mongodb server is present.

For usage hints please see section 6.3.4 (Text Indexes) of reference manual.
DATAMONGO-850 - Add support for full text search via $text

Using TextQuery and TextCriteria allows creation of queries using $text $search.

{ $meta : “textScore” } can be included using TextQuery.includeScore. As the fieldname used for textScore must not be fixed to “score” one can use the overload taking the fieldname to override the default.
DATAMONGO-976 - Add support for reading $meta projection on textScore into document.

We introduced @TextScore that can be used to mark a property to take { $meta : “textScore” }. Different to @Transient the value will be considered when reading documents.
The value can and will only get picked up if the score field is retrieved from the store.