Add support for Foundry 0.7.3

- Fixed an issue with the actor/item creation dialog that prevented
  it from working on Foundry 0.7.x versions.
- Removed obsolete translation string.
- Bumped minimum core version now that 0.7.3 is in beta.

templates/sidebar/entity-create.html

@@ -11,6 +11,5 @@
             <option value="{{this.value}}">{{this.label}}</option>
         {{/each}}
         </select>
-        <p class="notes">{{localize "ENTITY.TypeHint"}}</p>
     </div>
 </form>