Minor refactoring: commented code, public fields, etc.

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
JobGroup class refactoring

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>
Merge pull request #1 from oleg-nenashev/advanced_priority_queue

Code cleanup
Refactoring of messages

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>
Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
Merge pull request #2 from oleg-nenashev/advanced_priority_queue

Refactoring of messages
Refactored Strategies to be Extensions.

 * Added ExtensionPoint and made all Strategies Extensions.
 * Refactored and optimised priority to weight calculations.
 * Added more tests for calculations.
 * Bumped Jenkins version to 1.520 to use QueueListener
Added license information.
Slight tuning of weight calculation.
Refactoring (renaming only)
Added new PriorityStrategy extension.
Added new PriorityStrategy extension. (missed changes)
Fixed inner-class syntax error.
Updated PriorityStrategy to be Descriptable.
Added CLICause strategy.
Added BuildParameterStrategy strategy.
Refactoring and added protection against bad priority values.
Fixed broken test.
Fixed broken test.
Storing queue to disk to survive restarts.
Cleanup.