Implement configurable timeout for the ssh connection (launch) portion of EC2 Slave provisioning.
Code review fixes: Handling NaN and int overflow
Reworked template class to store an int, but expose a String to the jelly template - same as the instanceCapStr was doing.
Also added form validation and help template.
Merge pull request #64 from ericsmalling/launchtimeout

JENKINS-18993 - Implement configurable timeout for the ssh connection (launch) portion o...