Support negative values for integer and decimal property editors

src/Umbraco.Web.UI.Client/src/views/propertyeditors/decimal/decimal.html

@@ -2,7 +2,7 @@
     <ng-form name="decimalFieldForm">
         <input name="decimalField"
                type="number"
-               pattern="[0-9]+([,\.][0-9]+)?"
+               pattern="[\-0-9]+([,\.][0-9]+)?"
                class="umb-property-editor umb-number"
                ng-model="model.value"
                val-server="value"

src/Umbraco.Web.UI.Client/src/views/propertyeditors/integer/integer.html

@@ -2,7 +2,7 @@
     <ng-form name="integerFieldForm">
         <input name="integerField"
                type="number"
-               pattern="[0-9]*"
+               pattern="[\-0-9]*"
                class="umb-property-editor umb-number"
                ng-model="model.value"
                id="{{model.alias}}"