feat(ng-base-css): useNgBaseCss Component annotation field.

Introduces a useNgBaseCss field in the ```@Component``` annotation.

It defaults to true, but when set to false, the component will not
load any base CSS files.  For components that do not rely on base
CSS, loading a global CSS file can be a significant performance issue.

Best practices say that large global CSS files are an anti-pattern for
shadow DOM based apps.  ng-base-css allows apps to use this anti-pattern
to support legacy app design.

The useNgBaseCss field allows app developers to transition to
per-component styles and reap the performance benefits immediately.
chore(tests): Disable tests due to dartbug.com/19177
benchmark(tree): Add the TreeComponent benchmark.

This benchmark exercises component creatation.
perf: Use precomputed keys with injector for performance reasons.

Closes #1081
test(_specs): Add types, follow coding conventions
test(_specs_spec): remove tests that belong to guinness
fix(Http): Fix NoSuchMethodError in Http when cache set to true and
update documentation about cache usage.

Closes #1066
fix(Http): Auxiliary methods like get, put, post, etc. do not set type restriction on data being sent.

Fixes #1051
refactor(ng-repeat): refactor the fix for #1015
feat(element binder): Use a child scope instead of Scope.watch(context:o)

This is the only place where Scope.watch(context:o) is used and it is
in the way of optimizations.

For #1086
feat(scope): Deprecate Scope.watch's context parameter.

Scope.watch should no longer switch context.  Instead of saying

    scope.watch(expression, (v, _) { }, context: o);

Create a new isolate child scope

    scope.createChild(o).watch(expression, (v, _) { });
refactor(Scope): Pull ASTParser out of Scope into it's own library

For #1086
chore(ASTParser): Clean up and refactor the ASTParser

-> Make it injectable
-> Remove try/catch statements are extra state
-> Rename AstParser -> ASTParser
-> Rename ExpressionVisitor -> _ExpressionVisitor

For #1086
feat(scope): Expose Scope.watchAST as a public API

For #1086
feat(compiler): Precompute Scope.watch AST for TextMustache

For #1086
feat(compiler): Pre-compile Scope.watch ASTs for attribute mustaches

For #1086
feat(compiler): Precompute Scope.watch ASTs for bindings

For #1086