Add more code to facilitate actor implementation

Add more code to facilitate actor implementation

Added obtain() to Context
Added startGuardAsync(), in anticipation of adding guards.
Moved logRestXxx() from Util to HttpOperation.
Added actor.test to facilitate testing of actors.
Changed timeoutSec from long to int in various places.
Made a couple of methods public to support junit testing.

Most of the methods required Params to be passed, which indicated a
design issue.  Split Operator and Operation so that the Params could
be kept in a field and thus need not be passed to every method.
Basically, renamed OperatorPartial.java to OperationPartial.java and
created a new OperatorPartial.java.  Of course, this makes it look to
gerrit like it's all new code, when in fact, most of it is unchanged,
other than removing the Params argument to the method calls.  That
accounts for about half of the "lines changed" count.

Issue-ID: POLICY-1625
Change-Id: I9e98c9dadcbed145bf84deb06c9db1c864a3c24a
Signed-off-by: Jim Hahn <jrh3@att.com>