Fix EZP-19979: Class on ezxml tags are (almost) not handled

This pull request fix this issue : https://jira.ez.no/browse/EZP-19979

I did it like recommended in my previous PR (#314) :
* The first commit is here only for having something more readable, in my opinion.
* The second update the ezxml fieldtype XSL stylesheet for enabling "class" and "align" attributes that currently aren't rendered for some tags.

For the comments about the UNIX EOL that @patrickallaert did, I don't know how to see and correct it... I'm on Ubuntu.