New : add extrafield support on propal object
Edit extrafields on propal
Move substitution function for propal to common class & add extrafields display
Display linked propal information into invoice ODT
Add help about extrafields in ODT propal
Fix : incorrect function used to retrieve extrafields for propal
Add param to define key name in return array of substitution function
for propal
Fix : change to variable with unused name
Add information about linked proposal into basic ODT template for invoice
Fix : extrafields for propale were note saved after creation
User must have write permission to edit extrafields on propale
Fix : extrafields are not saved on update (propale)
Merge branch 'extra_propal' into extrafields
Add table for invoice extrafields
Prepare invoice admin page to add extrafield support
Add admin screen for extrafields on customer invoices
Add extrafields support when create a customer invoice
Edit extrafields on customer invoice
Retreive extrafield when fetch invoice
Show extrafields for object into invoice ODT document