feat(ng-model): Added ng-model-options

Added support for the debounce part of ng-model-options

Closes #969
Closes #974
fix(ng-repeat): handle the ref changing to null and back

This was broken in commit 09871cb29b5345d49929895b2a490360eee69244.

If the ng-repeat expression changed from an iterable to a null,
ng-repeat would not notice it.  This would cause further bugs as it
would not reset its state and the ref became a collection again (i.e.
once out of sync, it was gone forever.)

Closes #1015
chore(pubspec): requires DI >= 0.0.40

close #1016

The DI ".bind()" syntax has been used in angular since
3cf82a11fc187f9c439bfd58b66480adf204ca7e. It requires the DI version to
be at least 0.0.40
chore(run-test.sh): Use the dart bin configured by env.sh
chore: fix doc generation by putting it back into Travis
chore(docs): Fix master not getting kicked off after success in presubmit
chore(docs): fix for broken travis doc generation
chore(docs): make docs generate from the correct travis job
chore(docs): fix typos in Travis build scripts
chore(docs): comment for doc generation
chore(docs): debug Travis doc generation issue
chore(docs): fix env.sh for doc generation
chore(docs): export DARTSDK as well as DART_SDK from env.sh
chore(docs): run docs from stable to work around dartanalyzer bug in dev
fix(ViewCache): Use an unbounded cache in the ViewCache.

ViewCache was broken by the LruCache change in 3e60863.  Between
that change and this one, it was not caching any views.

Also, add a test.
fix(http): use location.href instead of toString

location.toString() fails when running with web_compomnents polyfill.
chore(docs): fix dartdoc indentation for application_factory
docs(Scope): explain `::` and `:` expression notation
chore(testing): upgrade guinness

Upgrade the Guinness library to fix the issue with `ddescribe` not working.

Closes #1029
feat(scope): added runAsync stable:true