Refactored and renamed "get-or-post-url" to "mkreq".

Created a number of helper methods as part of refactoring.

Further work is necessary to eliminate repetition and generalize helper methods.
Moved ssl-connect scheme definition from web.arc to ac.scm.
Small refactorings. Moved ssl-connect to ac.scm
Reorganized methods in web.arc. Writing new test script.
Removed response cookie parsing. Other minor refactorings.

Response cookie parsing is unnecessary and the previous implementation
was buggy -- it did not support multiple set-cookie lines in the
response.

I removed the functions to give the user consistent expectations -- mkreq and related
utility functions do not assist with interpreting the server response
beyond separating header from body and breaking the header into its
component lines. Response interpretation is entirely left to the user.

Response parsing utilities may still be worthwhile to implement here. A TODO was included to note this.

Thoughts for parsing utilities
--each header line should be tokenized as nested association lists
--keys for status line should be hard-coded as they are not in the
response. all other keys should be read from the response.
Completed the w/io macro to simplify usage of in out ports.

Also renamed several variables and functions to consistently refer to
key-value pairs in the url as query components instead of more generally
as arguments. For example, arglist is now querylist.
Small refactorings. Completed test suite. All tests pass.
Fixed a bug in to-query-str.
Refactoring to remove state from mkreq.
Now urlencode input querylist. Drafted defreq macro.
Completed defreq macro.
Added third interface feature -- mkuri. Needed by oauth library.
Implemented test showing to-query-str assumes inputs are url-safe.
Merge pull request #15 from brianru/http-client-lib

Refactored web.arc