Memory options for windows service

[Vlatombe]

Some additional enhancements to the managed slaves using windows services :

• When disconnecting a slave, there was still an issue with the 'host' used
• Disconnecting the slave now removes the service. This allows to re-register the service using the right credentials if they have been changed after the first connection
• Memory options have been added to the slave configuration (similar to jnlp, we may need to customize the java options)
• In case memory settings have been modified, disconnecting then reconnecting the slave copies jenkins-slave.xml with the updated configuration
• Some minor improvement on the expand logic on radioBlocks.

[kohsuke]

working on this now.

[kohsuke]

I've somwhat modified the change but merged this toward 1.448.