updating issues for 5.0

Completed information about new features and other enhancements from google doc version
Added entries for most LPs on Mike's list; made note in each LP. A couple LPs need
  clarification for me to write them; that is noted in LP.
Updated the ceilometer info in ops guide about database access
Added the pdf/pdf_relnotes.rst file

Release date is now set for 27 May.

Change-Id: Icc36b57348750789632533b3b63087f316c831aa
Merge "updating issues for 5.0"