[template] Move all js on head part

[camlafit]

Hi

Template system have move some js call on footer page (I presume to performance issue). But I'm not sure is nice to use it in default template :

• Defer attribute is now correctly supported (http://caniuse.com/#feat=script-defer)
• is harder to configure a proxy cache/concatenation
• override template is not intuitive (two template files to change/check head and footer)
• jquery dependencies

[techknowlogick]

We've now mostly moved to using webpack, and so we pack all JS into one file (kinda, webpack has a webloader that'll load the relevant bits needed).