Unified Color picker fixes (#9466)

* colorpicker: fix opening error when color is undefined

* colorpicker: replace spectrum picker by new color picker

* colorpicker: remove old spectrum picker directive

* annotations: use tinycolor for working with region colors

public/app/core/directives/spectrum_picker.js

@@ -1,41 +0,0 @@
-define([
-  'angular',
-  '../core_module',
-  'vendor/spectrum',
-],
-function (angular, coreModule) {
-  'use strict';
-
-  coreModule.default.directive('spectrumPicker', function() {
-    return {
-      restrict: 'E',
-      require: 'ngModel',
-      scope: false,
-      replace: true,
-      template: "<span><input class='input-small' /></span>",
-      link: function(scope, element, attrs, ngModel) {
-        var input = element.find('input');
-        var options = angular.extend({
-          showAlpha: true,
-          showButtons: false,
-          color: ngModel.$viewValue,
-          change: function(color) {
-            scope.$apply(function() {
-              ngModel.$setViewValue(color.toRgbString());
-            });
-          }
-        }, scope.$eval(attrs.options));
-
-        ngModel.$render = function() {
-          input.spectrum('set', ngModel.$viewValue || '');
-        };
-
-        input.spectrum(options);
-
-        scope.$on('$destroy', function() {
-          input.spectrum('destroy');
-        });
-      }
-    };
-  });
-});