fix(material/core): delete deprecated APIs

Deletes the mixin APIs that have been deprecated for a while and aren't used anywhere.

BREAKING CHANGES:
* `mixinColor` and `CanColor` have been removed. Use a host binding instead.
* `mixinDisableRipple` and `CanDisableRipple` have been removed. Use input transforms instead.
* `mixinDisabled` and `CanDisable` have been removed. Use input transforms instead.
* `mixinInitialized` and `HasInitialized` have been removed. Use a `Subject` that emits in `ngOnInit` instead.
* `mixinTabIndex` and `HasTabIndex` have been removed. Use input transforms instead.

Author: crisbeto