Merge pull request #224 from gdelhumeau/XWIKI-9738

XWIKI-9738: Finalize migration from workspaces to the new wiki API.
XWIKI-9733: Stracktrace during the data migration when upgrading from 4.5.4 to 5.3M2
[Misc] Bulletproofing
XWIKI-9684: Tag RSS feature is missing
* Move deprecated keys to deprecated section since we've now removed the TagRss page which was the only page using them
XWIKI-9742: Remove wiki syntax from translations in the Wiki module.
XWIKI-9554: Top Active Members lists users that are not members.

* Renaming the gadget.
XWIKI-9706: Velocity macro unrendered on Administration - Wiki.

* Removing the useless section of the administration.
[misc] Group the fields in the Solr schema based on the entity type to see more clearly what fields can be queried for a given entity type.
[misc] Search response is not available when debug info is displayed.
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* We need an encodig scheme for Solr field names in order to be able to use special characters. This is required for dynamic fields that we add for XClass properties, where the space/page name can contain special characters, especially when the XClass is created by an user.
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* We need a dedicated EntityReference serialization syntax that doesn't use characters which are not allowed in a field name (i.e. which have special meaning in a Solr query). For instance we cannot use Space.Class^prop in a field name because ^ is a special character in Solr query syntax. We need a serializer/resolver (so both ways) because we want to be able to extract the EntityReference from the field name when displaying search results highlighting.
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* Allow subclasses of AbstractSolrMetadataExtractor to overwrite the way an XClass property is indexed.
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* Add support for dynamic aliases for multilingual fields. The list of supported locales is not hard-coded anymore in the solrconfig.xml but taken from the search request.
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* Index the type of objects a document has. This way we can query object:Blog.BlogPostClass
XWIKI-9508: SOLR does not allow to match documents matching specific values in multiple xwiki properties
* Index the object property values on the document rows (i.e. along with the document information like document title and content) so that they can be queried when searching for documents. The following query are now possible: property.Blog.BlogPostClass.title:value AND object.XWiki.TagClass:tag
Merge pull request #226 from gdelhumeau/XWIKI-9554-4

XWIKI-9554: Top Active Members lists users that are not members.
XE-1348: WebRss doesn't support the tag parameter
XE-1349: Potential SQL injection in WebRss
XWIKI-9743: Activity Macro's RSS feed doesn't support passing multiple spaces or tags
XWIKI-9476: Impossible to import a large wiki from a XAR
* fix bug
XWIKI-9735: External links are overlapping with "My Activity Stream"
Merge pull request #225 from gdelhumeau/XWIKI-9742

XWIKI-9742: Remove wiki syntax from translations in the Wiki module