fix(ng-pluralize): use ${..} to interpolate

See: https://github.com/angular/angular.dart/pull/528#issuecomment-34892892

Closes #572
fix(ngModel): process input type=number according to convention, using valueAsNumber

Closes #574, Closes #575, Closes #576. 

Previous patches of relevance: #527, #415

Closes #577
fix(DateFilter): fix a wrong type

Closes #579
fix(compiler): support filters in attribute expressions

Fixes #571
Closes #580
style(ng-repeat): fix a typo shalow -> shallow (fix #581)

Fixes #581
style(ng-repeat): code cleanup

Closes #582
fix(di): Upgrade dependency of package di preventing problems with dart sdk 1.1 resolves #408

Fixes #408
Closes #583
fix(ngModel): ensure checkboxes and radio buttons are flagged as dirty when changed

Closes #569
Closes #585
chore(release): release v0.9.8
chore(perf): Get watch_group_perf running on Dart2js

DARTIUM:
========
fieldRead: => 58,240 ops/sec (17 us) stdev(0.0028)
fieldReadGetter: => 1,480,972 ops/sec (1 us) stdev(0.08649)
mapRead: => 1,720,752 ops/sec (1 us) stdev(0.05972)
obj.method?(): => 93,362 ops/sec (11 us) stdev(0.00549)
obj.method?(obj): => 79,881 ops/sec (13 us) stdev(0.00301)
add?(a, a): => 1,342,560 ops/sec (1 us) stdev(0.10907)

change-detect List[1000](RunTime): 61.251990689697415 us.

DART2JS:
========
fieldRead: => 372,422 ops/sec (3 us) stdev(0.0109)
fieldReadGetter: => 1,038,660 ops/sec (1 us) stdev(0.19283)
mapRead: => 721,103 ops/sec (1 us) stdev(0.04434)
obj.method?(): => 172,910 ops/sec (6 us) stdev(0.00801)
obj.method?(obj): => 161,329 ops/sec (6 us) stdev(0.00598)
add?(a, a): => 2,432,982 ops/sec (0 us) stdev(0.17624)

change-detect List[1000](RunTime): 145.12734924896597 us.
feat(scope2): Basic implementation of Scope v2
feat(Scope): Brand new scope implementation which takes advantage of the new change detection
fix(change detection): Fix for comparing string by value
refactor: minor code cleanup / fixes
chore(scope): remove watchSet API
feat(scope): Allow expressions on non-scope context
chore(demo): update to work with new scope
fix(scope): allow sending emit/broadcast when no on()
feat(zone): Allow escaping of auto-digest mechanism. 

Closes #557
chore(style): code cleanup