Improvements to POIs import config

unified queries in one file, datasource differences extracted to
solrconfig.xml file. Also added comments to each import query to show
what is imported.
Merge pull request #3 from luisromangz/112475-ConfigImprovements

Improvements to POIs import config
Added missing file.
Merge pull request #4 from luisromangz/112475-ConfigImprovements

Added missing file.