ReqMgr2 package and modules naming

-making happy all WMCore consistency of naming
    guardians: CamelCase for package and module names
-static content dir is ReqMgr
-test/data - ReqMgr, shared with ReqMgr1
-no 2 names in a directory differ only in case since MacOS+git
    can't apparently handle that properly (!)
Merge pull request #4633 from zdenekmaxa/reqmgr2-renaming-modules-packages

ReqMgr2 package and modules naming
merge reqmgr db and wmstats requsest type documents
Implement the Tier-0 Mode

The Tier-0 needs are very special, and we don't have yet a fully
flexible and functional safe mode. This implements an specific
Tier-0 mode which is suitable for Tier-0 custodial, move subscriptions
although it has a few bits hardcoded.
Merge pull request #4628 from ticoann/reqmgr2_wmstats

request2 db and wmstats request data merge
Support T0 insertion through the WMBSHelper

Extend the createSubscription method to encapsulate WMBS and
DBSBuffer injection in the database, move the old createSubscription
to _createSubscriptionsInWMBS
Merge pull request #4634 from dballesteros7/morePhedex

Implement the Tier-0 Mode
Merge pull request #4630 from dballesteros7/t0-1

Support T0 insertion through the WMBSHelper