only load head modules once

the startup module triggers mw.load which loads all head modules
however the line below it also embeds the same script tag and as a result
mf-application.js gets loaded twice. Added mobile.head to dependencies of
mobile.startup to ensure that gets loaded too

Change-Id: I2c9f6ccc30743704bdc1ac51a864106bf50029dc
load mobile.startup at bottom of page

the javascript should load at the end of the page

Change-Id: I6c575a053a3de53a7e13b3bcfaf70b22523c755b
Merge "only load head modules once"
Merge "load mobile.startup at bottom of page"