regex_conversion_impl
=====================

A conversion similar to a series of sed 's' commands.  A list of search-replace 
rules is applied to the input buffer repeatedly until the result no longer 
changes; the state of the buffer at this point is result is the output of the 
conversion.  Each rule is examined for applicability in order; on success, 
the rule is applied.  The search is then restarted from the beginning of the 
list.  Processing only ceases when the list has been examined from start to 
finish with no applicable rule. (Poorly designed rules can therefore produce
infinite loops.)

add 
===

	some_rc add search replace

Appends a new rule to the list in `some_rc`; the new rule has `search` as the
element sought and `replace` as the element that replaces it.  `search` may
contain regular expression elements (as implemented by boost) and `replace`
may contain elements like `\1` to refer to parenthesised expressions in
`search`.

remove
======

	some_rc remove search replace

Removes the rule mapping `search` to `replace` in the rule list of `some_rc`.

list
====

	some_rc list

Emit the list of rules for `some_rc`.