Turn markup related characters into bracket notation.
Allowing markup characters in the phrase is problematic for a number of reasons, including:
So we detect and modify them.
… THIS FILTER Locale::Maketext::Utils::Phrase::Norm::Ampersand.
This is not enforced anywhere since we want to assume the coder knows what they are doing.
Turns <>'" into appropriate bracket notation.
& is handled in its own driver.
This is issued when " is encountered.
This is issued when ' is encountered.