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.
added more support for the git plugin
Add emma code coverage publisher support
Move to using a closure to define the thresholds for coverage. Allow for definining min/max for class/line/block/method/condition separately or using an IntRange.
- Don't use keyword for method name, so switch to using names like classThreshold and methodThreshold.
- Add trailing newline at end of EmmaContext
- Add precondition checks for values in EmmaContext
- Enforce that max can't be lower than min when setting min value explicitly (otherwise the range can get goofy).
- Set condition range default max to 80
- when setting max percent for a type, enforce that min is <= new max
- add unit tests for testing values out of valid range
added some default parameters
reproduce the defaults of the Git Plugin 2.0 while keeping compatibility
Merge pull request #108 from jenkinsci/git-closure

added more support for the git plugin
Merge pull request #97 from justinharringa/patch-1

Added ItemDiscover, ItemCancel, and ScmTag permissions to the Permissions enum
Releasing 1.20
Bumping to next rev