IE8 login !@#!!@!

* Fix # 433
Various IE8 fixes !#!@@!

indexOf / trim
wegas-image content_template fix...
 :anger:
Page editor, "add button" again

*Fix # 435
merge fix
Merge branch 'master' of github.com:Heigvd/Wegas

# By Yannick Lagger (3) and Francois-Xavier Aeberhard (2)
# Via Yannick Lagger (3) and Francois-Xavier Aeberhard (1)
* 'master' of github.com:Heigvd/Wegas:
  Refactor wegas.core.event to wegas.core.event.client and wegas.core.event.internal
  Fix last commit
  Fix #423 account autocompletion
  Remove useless TeamTreeViewEditor class
  Refactor CSSLoader plugin