Humble beginings
Ignore everything (with excetptions)
Functional request header rewriting

The regex gets scanned for named captures which are than indexed
and used in the request URL recipe (configurable).
Drop boost::xpressive

and revert back to boost::regex which seems to parse
Perl-like capture groups just fine (unlike xpressive
which wnats Python style, sic)
Resp/Req rewriting works

The matching approach is a bit different now -- the region is searched
for next match and the replacement is performed in line.
Use C++ strings and handle non-capturing groups
Only remember match if not empty
Handle muliple req/resp patterns

Tried in order, first martched first used.
Add response rewrite rule
Reconstruct headers before matching
Refactor
Rewrite body too
Factor out impl from test
Configure from XML
Add XML config test
Merge remote-tracking branch 'origin/master' into rewrite-filter
Fix warnings
Include filter in the static factory
Log when the filter is invoked
Use yaz_log