search_api_solr 8.x-1.0-rc4

This is the fourth release candidate of the Search API Solr Search 8.x-1.0. The minimum "officially supported" Solr version is still 4.5.1. The latest available Solr version at the moment is 6.6.0 and is supported, too :-)
If you use Solr 6.5.x you have to be aware that there's a known issue within Solr itself that always leads to zero results in combination with search_api_autocomplete: #2869529: Autocomplete (and spell checking) is broken on Solr 6.5.x, Solr 6.6 will solve the issue.
Since this bug is fixed in Solr 6.6.0 we declare Solr 6.5.x as unsupported.

We have a known issue that needs to be fixed in combination with a Search API itself: #2882347: Serialization of config fails
This issue currently blocks the final 1.0 release.

This release candidate only works in combination with search_api 8.x-1.1!

The most important change that happened during the beta phase was the introduction of SolrConnector classes that allow Solr providers to do their specific adjustments without hacking the Solr backend class anymore. Local and standard installations will be supported by this module out of the box. An corresponding upgrade path is included. For other installations you can check these issues:

• Acquia: #2817387: Provide a proper SolrConnector plugin
• Pantheon: #2821770: Pantheon Connector: Plan for next release?
• Open Solr: #2819821: OpenSolr Support

If you update an existing installation, the first thing you should do is to deploy the latest Solr config files from the module's solr-conf folder and afterwards delete all the data from the index and start a re-indexing process!

The basic API is considered complete now and the essential stuff works very well, but we still have incomplete features which will be addressed after the final release of 1.0:

• #2682347: Expose solr-only fields to views
• #2831842: Prepare usage of Solr's suggester component for autocomplete suggestions and re-enable multiple "indexes" per Solr Core later
• #2873227: Implement Solr specific views cache backend
• #2864967: Fix multisite search/multiple indexes on one core, tho it might break spell checking, autocomplete and suggesters
• #2863611: Support range facets
• ...

Complete list of changes since rc3:

• Issue #2884867 by mkalkbrenner: #2884867: Run tests on Solr 6.6.0
• Issue #2869529 by mkalkbrenner: #2869529: Autocomplete (and spell checking) is broken on Solr 6.5.x, Solr 6.6 will solve the issue
• Issue #2884494 by mkalkbrenner, ayalon: #2884494: Don't always return all fields from solr index
• Issue #2881587 by Les Lim, mkalkbrenner: #2881587: Highlighter erroneously overwrites excerpt.snippets and excerpt.fragsize configs
• Issue #2881651 by drunken monkey: #2881651: Add the Solr document to the result item as extra data