Fixes issue with command escaping on Windows

Fixes bug: #1210912

Special characters like <, > or ' need to be escaped on Windows when used
with "cmd /C <command>" as implemented in _run_shell_command

In order to avoid escaping issues, shell spawning has been replaced with
direct command execution. As a consequence, grep/egrep command pipes have
been replaced with Python regular expressions where appropriate.

Change-Id: Idd50fd24f300bce655f99d42cb96e37d29d4cb14
Stop checking periods in commit messages

This breaks various peoples fingers and there was no overwhelming
community support, nor historical evidence, for enforcing the proposed
rule in either direction.

Change-Id: Id2a5af9bb8a49af0a2f94b38a8e7d5ef1208e627
Merge "Fixes issue with command escaping on Windows"
Merge "Stop checking periods in commit messages"