Fail when ssl parameters are missing and rabbit_use_ssl is set to true

This commit causes the run to fail is rabbit_use_ssl parameter is set
to true but the ssl related parameters remains undef.

Change-Id: If621de7ed4432c4ef79d18cee4da822ebadb0a4f
Enable heat server to be run in SSL mode

This commit allows one to specify cert and key file
to run heat server in SSL mode.

Note: The flag use_ssl per se is not used in heat yet,
its purpose here it to verify collateral parameters.

Change-Id: I94d0b461adc752b028770aea71bf4e4612722539
Fix title of database sync Exec in mysql class

The mysql class incorrectly defined an Exec collector to match on 'heat-manage
db_sync', which is not a real Exec in the catalog. The collector silently
failed to find this resource and the notify relationship between the database and the
sync command was never created. This changes the collector to match on
heat-dbsync, which is a real exec defined in init.pp.

Change-Id: Icc8ceb25b525ba83e66c719abca31799a4d2d223