Add new standard rule to handle encoding text file

Hello,

It will be very useful to have a standard rule to check encoding text file as : *.java, *.jsp, *.xml, *.properties, *.sql
Indeed, following my experience in big project development there's many time error due to heterogeneous encoding file.

So a simple standard to check every text file in same encoding could be very useful.
Let me know, if my point of is relevant.

Thanks.