Make comment generic for all files

htdocs/langs/en_US/ftp.lang

-# Dolibarr language file - en_US - ftp
+# Dolibarr language file - Source file is en_US - ftp
 CHARSET=UTF-8
 FTPClientSetup=FTP Client module setup
 NewFTPClient=New FTP connection setup

htdocs/langs/en_US/help.lang

-# Dolibarr language file - en_US - help
+# Dolibarr language file - Source file is en_US - help
 CHARSET=UTF-8
 CommunitySupport=Forum/Wiki support
 EMailSupport=Emails support

htdocs/langs/en_US/holiday.lang

-# Dolibarr language file - en_US - holiday
+# Dolibarr language file - Source file is en_US - holiday
 CHARSET= UTF-8
 
 HRM=HRM

htdocs/langs/en_US/install.lang

-# Dolibarr language file - en_US - install
+# Dolibarr language file - Source file is en_US - install
 CHARSET=UTF-8
 InstallEasy=Just follow the instructions step by step.
 MiscellaneousChecks=Prerequisites check

htdocs/langs/en_US/interventions.lang

-# Dolibarr language file - en_US - interventions
+# Dolibarr language file - Source file is en_US - interventions
 CHARSET=UTF-8
 Intervention=Intervention
 Interventions=Interventions

htdocs/langs/en_US/languages.lang

-# Dolibarr language file - en_US - languages
+# Dolibarr language file - Source file is en_US - languages
 CHARSET=UTF-8
 
 Language_ar_AR=Arabic

htdocs/langs/en_US/ldap.lang

-# Dolibarr language file - en_US - ldap
+# Dolibarr language file - Source file is en_US - ldap
 CHARSET=UTF-8
 DomainPassword=Password for domain
 YouMustChangePassNextLogon=Password for user <b>%s</b> on the domain <b>%s</b> must be changed.

htdocs/langs/en_US/mailmanspip.lang

-# Dolibarr language file - en_US - mailmanspip
+# Dolibarr language file - Source file is en_US - mailmanspip
 CHARSET=UTF-8
 MailmanSpipSetup=Mailman and SPIP module Setup
 MailmanTitle=Mailman mailing list system

htdocs/langs/en_US/mails.lang

-# Dolibarr language file - en_US - mails
+# Dolibarr language file - Source file is en_US - mails
 CHARSET=UTF-8
 Mailing=EMailing
 EMailing=EMailing

htdocs/langs/en_US/main.lang

-# Dolibarr language file - en_US - main
+# Dolibarr language file - Source file is en_US - main
 CHARSET=UTF-8
 DIRECTION=ltr
 SeparatorDecimal=.

htdocs/langs/en_US/margins.lang

-# Dolibarr language file - en_US - marges
+# Dolibarr language file - Source file is en_US - marges
 CHARSET=UTF-8
 
 Margin=Margin

htdocs/langs/en_US/members.lang

-# Dolibarr language file - en_US - members
+# Dolibarr language file - Source file is en_US - members
 CHARSET=UTF-8
 MembersArea=Members area
 PublicMembersArea=Public members area

htdocs/langs/en_US/opensurvey.lang

-# Dolibarr language file - en_US - opensurvey
+# Dolibarr language file - Source file is en_US - opensurvey
 CHARSET=UTF-8
 Survey=Survey
 Surveys=Surveys

htdocs/langs/en_US/orders.lang

-# Dolibarr language file - en_US - orders
+# Dolibarr language file - Source file is en_US - orders
 CHARSET=UTF-8
 OrdersArea=Customers orders area
 SuppliersOrdersArea=Suppliers orders area

htdocs/langs/en_US/oscommerce.lang

-# Dolibarr language file - en_US - oscommerce
+# Dolibarr language file - Source file is en_US - oscommerce
 CHARSET=UTF-8
 OSCommerce=OS Commerce
 OSCommerceSetup=OS Commerce module setup

htdocs/langs/en_US/other.lang

-# Dolibarr language file - en_US - other
+# Dolibarr language file - Source file is en_US - other
 CHARSET=UTF-8
 SecurityCode=Security code
 Calendar=Calendar

htdocs/langs/en_US/paybox.lang

-# Dolibarr language file - en_US - paybox
+# Dolibarr language file - Source file is en_US - paybox
 CHARSET=UTF-8
 PayBoxSetup=PayBox module setup
 PayBoxDesc=This module offer pages to allow payment on <a href="http://www.paybox.com" target="_blank">Paybox</a> by customers. This can be used for a free payment or for a payment on a particular Dolibarr object (invoice, order, ...)

htdocs/langs/en_US/paypal.lang

-# Dolibarr language file - en_US - paypal
+# Dolibarr language file - Source file is en_US - paypal
 CHARSET=UTF-8
 PaypalSetup=PayPal module setup
 PaypalDesc=This module offer pages to allow payment on <a href="http://www.paypal.com" target="_blank">PayPal</a> by customers. This can be used for a free payment or for a payment on a particular Dolibarr object (invoice, order, ...)

htdocs/langs/en_US/products.lang

-# Dolibarr language file - en_US - products
+# Dolibarr language file - Source file is en_US - products
 CHARSET=UTF-8
 ProductRef=Product ref.
 ProductLabel=Product label

htdocs/langs/en_US/projects.lang

-# Dolibarr language file - en_US - projects
+# Dolibarr language file - Source file is en_US - projects
 CHARSET=UTF-8
 Project=Project
 Projects=Projects