[DS-1456] Make webapp.s register in a new database table when started, so we can
list them later.
Replace kooky URL calculation with fetching it from the configuration.
Reorganize, refactor, implement an alternative MBean approach for trial.
Record 'isUI' in database; add code to 'dspace version' to consume the table.
MXBean approach didn't pan out, so remove (most of) the code.
Remove added context parameters no longer used.
When listing webapp.s, delete records for any not found living.

This sends a HEAD request to the registered URL for the webapp and
assumes that the app is dead if result is not 200.

This change caused a cascade of changes to the treatment of the
database table, because the DBMS layer insists that a table's primary
key be INTEGER.  It was necessary to introduce a new column for the
purpose.  This also means you can have more than one running instance
of the same UI, if you wish.  But it also means that the sequence
required by the new column will overflow after about 2 billion starts.
Declare use of slf4j-api.
Export all collections of a community recursively
Migrate solr config files to solr4, add standalone log4j configuration (use log4j daily appender logger) for solr and reference it in web.xml, merge web.xml custom dspace with web.xml solr4 default
Add standalone lucene-queryparser (before went with core), added specific solr.version property, update elasticsearch to avoid references to lib <lucene4
From version 4.3.0 aims for complete logging flexibility, it don't include logging jars in the .war file, so we provide them with the inclusion of commons-logging
Migrate discovery to solr4
Migrate search to lucene 4
Migrate statistics to solr4
Exception surrounded modified in solr4
Update to new solr server object
Update modules to solr4
Update elasticsearch references to new version
Fixing usage statistics logging by adding update chain for uid