ReqMgr2 auxiliary database

-auxiliary database reqmgr_auxiliary definition
-ReqMgrAux couchapp
-root package name change WMCore/ReqMgr -> WMCore/reqmgr
-cron job for software versions updating defined
-Group, Team, Software REST API including updates
-Request GET REST method
-couchdb database convenience wrapper
-ReqMgr2 test / interaction client test/data/reqmgr/reqmgr.py

Unittests will be included in test/python/WMCore_t/reqmgr_t
Merge pull request #4619 from zdenekmaxa/reqmgr2-reqmgr_auxiliary-database

ReqMgr2 auxiliary database