s1689: factor out common command-line options
s1689: add cookie identification method

Mostly plumbing to pass the new "cookie" argument down to the
Client objects. If present, the string is currently just
added as a CADC_SSO cookie to request headers to mimic the single
sign-on behaviour with browsers. For now the presence of a
cookie will override a supplied cert, since http will be used
(which is faster than https required for certs).
s1689: clean up logic/messages
s1689: missed a cookie
s1689: remove debug statement
s1689: fix bugs detected when running tests
s1689: fix loggers
s1689: fix vofile unit test

The tests were failing an "isInstance" assertion for the
Connection class. Rather than using the spec= argument (which
caused a different failure due to the cookie initialization),
use the actual Connection class and simply patch the get_connection
method.
s1689: tests for vos Client constructor
s1689: missed vrmdir in parser refactor
s1689: remove debug message
s1689: use scoped cookies
Merge pull request #45 from edwardchapin/s1689

S1689: Add scoped cookie support to VOS clients