feat($parse): support the ternary/conditional operator

Closes #272
fix(ng-class): exportExpressionAttrs for ng-class, ng-class-odd, ng-class-even
chore(.agignore): add .agignore to prune command line searches

I use the Ag tool (like ack, grep, etc. - ref
https://github.com/ggreer/the_silver_searcher) for searching.  The
.agignore file is used to prune the search space.
feat($parse): support the integer division operator

Closes #233
Remove WindowlessMetadataExtractor
test(ng-mousewheel): fix ng-mousewheel test
fix(parser): Add caching to the dynamic parser.

This change cut memory allocations for some actions in the Todo
demo app by 50%.
chore(perf): reflect speed test
feat(scope): Implement lazy scope digest
feat(repeater): implement shallow repeater
chore(npm): update karma-junit-reporter version
feat(repeater): implement shallow repeater
feat(scope): implement scope.$disabled
fix(parser): Add ternary support to the static parser
fix(static parser): Allow newlines in expressions.

Closes #297
chore: ignore .DS_Store file
wip: NgForm validation
wip: form upgrades