(PE-5859) Keep entire request URI matching regex

When wrap-proxy is called with a regex, keep the entire
portion of the request URI matching the regex rather than
replacing it in the rewritten URI.
(PE-5859) Address PR comments

Add a test where nothing is prepended to the proxied URI
when a regex is given to the wrap-proxy function. Add some
docs on the new behavior of the regex functionality. Bump
the version number to 0.2.0-SNAPSHOT for upcoming release.
(PE-5989) Change "prefix" to "path" in docs
(PE-6036) Add cache-control handler and tests for wrap-add-cache-header

This commit adds a wrap-add-cache-header utility handler function that
adds cache-control headers to GET and PUT requests and tests that make
sure that it doesn't clobber existing headers in responses, handles
nil responses by ignoring them, and only adding headers to get
and put requests.
(PE-5859) Strip trailing slash from remote uri

Strip the trailing slash from remote-uri-base so that repeat
slashes are not present when building the path of the
rewritten URI.
Merge pull request #19 from steveax/PE-6036-add-cache-control-headers

(PE-6036) Add cache-control handler and tests for wrap-add-cache-header
Merge pull request #18 from fpringvaldsen/PE-5859-preserve-regex-prefix

(PE-5859) Keep entire request URI matching regex