Release Notes - 5.1.1

This commit contains the following files to review:

* 050-known-issues.rst - contains 5.1.1 known issues
* resolved-issues-511.rst - contains 5.1.1 resolved issues

Note that 040-resolved-issues.rst has only 5.1 bugs issued, so
there is no need to focus on it.

Change-Id: I2f3a4f6b108eb111cd0b4d275a080da429373e7b
Merge "Release Notes - 5.1.1" into stable/5.1