set es version to 0.90.0
remove uncached
change DistinctDateHistogramFacetProcessor to DistinctDateHistogramFacetParser
WIP FacetCollector
use new facets api in tests
change plugin registration
rename StringDistinctDateHistogramFacetCollector
adopt InternalDistinctDateHistogramFacet
adjust LongDistinctDateHistogram classes
fix NullReference Exception
use dateTime to account for interval
add some more comments
migrated StringDistinctDateHistogramFacet to ES v0.90.0
made this plugin ES v0.90.0 compatible
fixed pom.xml
fixed indentation
added changes entry about renaming package and namespace
changed long to numeric