DATASOLR-188 - Convert to Asciidoctor for reference documentation.

Migrated existing docbook content to Asciidoctor.

Original Pull Request: #40
DATASOLR-181 - Remove deprecations.

Remove GeoLocation, Distance, BoundingBox and Facet.pivotFields.
Update documentation and pararmeter names.
Rename GeoLoactionConverter.
DATASOLR-183 - Updated changelog.
DATASOLR-190 - Updated changelog.
DATASOLR-190 - Prepare 1.3.0.RC1 (Evans RC1).
DATASOLR-190 - Release version 1.3.0.RC1 (Evans RC1).
DATASOLR-190 - Prepare next development iteration.
DATASOLR-190 - After release cleanups.