perf(nodecursor): do not grow/shrink the nodes list

This also enables one to construct a NodeCursor with a fixed size list
of nodes.
style(ng-repeat): correct typing for nodes list
perf(dom): improve dom cloning speed
chore(forms): add demo for repeatable forms

Closes #1044
Fix HashMap undefined due to missing import

Closes #1280
perf(watch-group): remove expression coalescing

Coalescing is rare but slows down WatchGroup creation.

Closes #1328
refactor(angular.dart): remove undefined export

ShadowRootAware is defined in annotation.dart and not in annotation_src.dart.

Closes #1313
feat: add option to use external css rewriter in template_cache_generator.

The provided rewriter will be used to transform every css read by the
TemplateCache, the original css is provided on stdin, and result is read
from the stdout of provided binary.

TESTING:

The test uses a simple sed script to exercise the integration.

The test runs only if sed is present on the running system.  The test
uses CSS with simple rules that are being translated for RTL locales.

Closes #1052
fix(scope): increase default ScopeDigestTTL to 10 iterations
Revert "perf(dccd): Drop useless checks"

This reverts commit 209d14f29f1dc438f6d5ab8ec1ba9f162f90de60.