This one-line change gives the auto_bootstrap config parameter the ability to be overridden by a system property.
As I understand things, setting this false is generally a one-time initial set-up item, and providing this will be potentially easier than swapping out yaml file items when the need to set this false arises.
The handling is the same as was already implemented for replace_address and the like, look to the system property, and default that to the yaml config value.
This also will also allow a start-up agent (like Priam) to influence the setting from within it's control over Cassandra's start-up behaviour
Patch was generated against 1.2 branch but applies ok to 2.0 as well. (It would be great if this could be applied to both code lines)