fix bugs on margin reports
update changelog
better margin calculation (especially for credit notes)
Merge pull request #1250 from altairis-fr/margin1

fix bugs on margin calculation and margin reports
Fix: Bad property
Fix: security sql injection
Fix: security sql injection
Merge remote-tracking branch 'origin/3.4' into 3.4_backported

Conflicts:
	ChangeLog
Add ref_customer into list

Conflicts:
	htdocs/compta/facture/list.php