ReqMgr2 request injection prototype

-created new package DataStucts containing Request, RequestTypes and
    RequestStatus definition
-DataStructs/Request contains validation of input request arguments
-Service/Request.post - request injection method - entire ReqMgr1 injection
    flow is now covered, though a number of request arguments manipulations is
    not entirely figured out, but majority is.
    Spec instantiation and Couch storing finished.
-Service/Request.delete method implemented.
-reqmgr2.py client script able to create, delete, query requets in ReqMgr2.

@ticoann please review. basically each TODO designated block is a smaller or
larger topic for discussion.
ReqMgr1, 2 - StoreResults injection

Create StoreResults.json request template capable of injecting
into both ReqMgr1,2. Some requisite values e.g. CmsPath do not
seem to be accessed in the spec implementation.
Also, definition of splitting parameters changed compared to
how StdSpects/StoreResults.py defines them. So currently,
this new StoreResults request would be treated in ReqMgr exactly
the same way like other request types, no special checks or
assignment conditions, roles, etc exist yet. This is for ReqMgr2.
Merge pull request #4702 from zdenekmaxa/reqmgr-storeresults-injection-and-template-2

ReqMgr1, 2 - StoreResults injection
Merge pull request #4701 from zdenekmaxa/reqmgr2-request-injection

ReqMgr2 request injection prototype
Merge branch 'master' of https://github.com/dmwm/WMCore into reqmgr2_get_test

Conflicts:
	src/python/WMCore/ReqMgr/Service/Request.py