Fix regular expressions in antisamy.xml

[faf0-addepar]

Fix the following regular expressions:

• paragraph (used for alt and abbr attributes): Questions marks need to be encoded in the used contexts, and must not appear otherwise. Remove the question mark as a permitted character.
• name attribute regular expression: The - character should be escaped, although in this instance it is not strictly necessary. The _ character is escaped, although it doesn't need to be escaped. Clean up the regular expression by escaping - and not escaping _.

[nahsra]

I think these changes are probably fine, but can you give some examples on why these expressions need to allow these characters? You say "incorrectly", but I'm confused as to what that means. I guess there's a difference between we should "correctly", "legally" and "reasonably" allow.

[faf0-addepar]

@nahsra I updated the description of this PR to answer your questions