New features to ProjeQtOr

Actually, the "days before warning" was supposed to highlight jobs that should have begun, not be done, according to the specifications. However, they never used the feature
For example, if we needed to order a piece that would take 5 days to ship, 5 days before we needed to have an indicator that job "Order piece" should have begun, or something like this.

Hi,

Just to notice you I made some improvements to the "select multiple" feature you already included: github.com/papjul/projeqtor/commit/9d315...7691512f4ae399facf00 (remember to only copy the changes as your branch is far more advanced)

List of changes:
- Fixed some issues reported in the console log
- Make select multiple a CheckedMultiSelect, this makes the select more intuitive by using checkboxes
- This also help support CheckedMultiSelect to refresh another CheckedMultiSelect in reportsParameters (using "store" feature from Dojo) like you do with regular Select

I don't know why but the external/dojox/form/resources/* folder was somehow not in ProjeQtOr package, so I had to get it back from Dojo upstream 1.10.7 (I only copied the .css I needed but the folder has a lot of other resources).

Thanks in advance,