Add .replace eval util

[brandonscript]

For a regular expression replace, would be:

[[control.attribute:replace(/regularexpression/*modfiers*|replacement)]]

We may need to have the delimiters be dynamic, like so (pseudocode):

• Identify the first character
• Search for the next occurrence of that character NOT preceded by a backslash
• Everything in between that start and end delimiter should be considered part of the regular expression
• Characters after the delimiter but before the | separator are modifiers: i (case insensitive), g (replace all occurrences of the match).