Added ItemDiscover, ItemCancel, and ScmTag permissions to the enum

These additional permissions should be useful for other standard permissions.
Reorder enums to reflect ordering in the Jenkins GUI

This is more of a readability enhancement which could potentially be useful in the event that other permissions are added to Jenkins in the future.
Adding support for Associated Files plugin
Ignore classes directory used by Intellij Gradle plugin default.
Merge pull request #124 from abayer/associated-files

Add support for Associated Files plugin
Add support for parameterized trigger as build step.
Adding support for NodeParameters and BooleanParameters for parameterized trigger.
Moving trigger parameters into their own method, reconciling it with multijob plugin usage
Merge pull request #126 from abayer/parameterized-trigger

Add support for parameterized trigger as build step.
Move all *Context classes from being static/inner classes

Also moved anything with a sub-context into a separate package.

Note that I briefly had all the beans within contexts moved to
separate classes too, but then realized that was unneeded. That
probably left some artifacts of the temporary change around in terms
of the diff, with classes moved around some.
Cleanup whitespace, imports.
Merge pull request #129 from abayer/resolvestrategy

Move all *Context classes from being static/inner classes
added more support for the git plugin
mark 1.20 as incompatible with previous versions
Add support for throttle-concurrent-builds-plugin
Merge pull request #127 from abayer/throttle-concurrent

Add support for throttle-concurrent-builds-plugin
Add support for archiveArtifacts / allowEmpty

In adding this, also offers a closure form for specifying archiveArtifacts options
Merge pull request #121 from ki82/master

Added support for Jenkins JsHint Checkstyle plugin as an report publisher
Using Linked List to allow showing jobs in the order that they were created
Merge pull request #132 from quidryan/master

Using Linked List to allow showing jobs in the order that they were created