MySQL handshake has a configurable version_string

MySQL handshake has no a configurable version_string parameter in
service section.
The default value is the server version of the embedded mysqld library.

Set option example:

version_string=5.5.37-MariaDB-log

Default is similar to:

5.5.35-MariaDB
Merge branch 'fix-423' into release-0.6
Configuration & Usage Scenarios document updated

Configuration & Usage Scenarios document updated with new
“version_string” service parameter
0.6.0 Release

0.6.0 Release
Documentation update for 0.6.0 release

Documentation update for 0.6.0 release