Drop support of parameter decorators

[shuhei]

The babel team is going to forbid people from monkey-patching the parser.

https://github.com/babel/babel/pull/3204

Parameter decorators used in Angular 2

DI for directives

• @Attribute: Not so necessary? Can we use @Input instead of this?
• @Query: Replaceable with @ContentChild and @ContentChildren?
• @ViewQuery: Replaceable with @ViewChild and @ContentChildren?
• @Host: The host directive's providers http://victorsavkin.com/post/126514197956/dependency-injection-in-angular-1-and-angular-2

  Pure DI

• @Inject: Probably be necessary for advanced developers?
• @Optional: Probably necessary for advanced developers?
• @Self: Not so necessary for app developers? The same element's providers http://victorsavkin.com/post/126514197956/dependency-injection-in-angular-1-and-angular-2
• @SkipSelf: Not so necessary for app developers?

https://angular.io/docs/ts/latest/api/#!?apiFilter=metadata

[JonnyBGod]

Why remove @Query?

[shuhei]

@JonnyBGod Because the parameter decorator syntax cannot be parsed by Babel. This plugin used to monkey-patch the Babel's parser but the newer version of Babel has forbidden monkey-patching on its parser.

By the way, you'll be able to achieve similar things as @Query by @ContentChildren.