Use mw.Api.postWithToken( 'edit' ) when possible

Saves us the trouble of getting the edit token ourselves, or when
replacing mw.Api.postWithEditToken, we don't need to load an extra
module just for wrapper function which does exactly the same.

Additionally, added parenthesis to scope new operator where used
in the lines I touched.

Change-Id: Ic540e5a1f1a38fc41823b8d50340b57f12d1c482
Merge "Use mw.Api.postWithToken( 'edit' ) when possible"