Merge branch 'release/1.1.0'
admin: bumped version numbers
reliability: do not raise exception for missing config file

Log an error message rather than raising an exception when a
sub-configuration file is missing. This relates to issue #75 and
prevents the Server getting locked in a broken state when a
Database config file has been deleted or moved.
+func: add unregister_databaseConfig method to SimpleServer
+func: add cheshire3-unregister command

Closes #75
docs: update release versions, dates and CHANGES
Merge branch 'hotfix/1.1.1'
Merge commit '1.1.1' into develop

Conflicts:
	VERSION.txt
	cheshire3/internal.py