Server now returns 503 when at capacity.

Catch this. For backwards compatibility with earlier versions of Taverna Server
we catch 403 in the run create code and re-raise as a server capacity error.
Server now has a limit on concurrently running runs.

A 503 is returned if the limit would be breached so catch this and return the
appropriate response to the caller when a run is started.
Test for max concurrently running runs.

Make sure it is less than or equal to the total run limit.
t2-run-workflow: Cope with hitting max running runs.

Informs the user and deletes the run for now.
t2-server-stress: Cope with hitting max running runs.

Backs of for 10 seconds before retrying if the server doesn't start a run due to
overcapacity. As this is a script to stress test then it is appropriate to wait
and continue running. This keeps the server at full capacity within its
configured limits.
Ensure all unit tests delete runs that they create.

Some tests were not deleting runs. This was being hidden by the fact that the
last test run was (randomly, so a coincedence) one that tested
Server#delete_all_runs.

Tests now run correctly if the run limits of both existing and executing runs
are set to 1.
Trivial fix for an "ambiguous code" warning.

Apparently some things consider the following to be ambiguous:

 read_body &block

Make explicit to be on the safe side by adding brackets around the parameter.
Internal fix to delete behaviour.

When the remote attribute is not found then an exception is raised but then
silently ignored. If this seems an odd way to go about things it is in
preparation for streamlining the behaviour of all HTTP methods in the connection
class.
Mark deleted runs as such in their Run object.

If a run has been deleted from the server, flag this in the local ruby Run
object. This is useful for various bits of lifecycle management.
[TAVSERV-308] Run#permissions returns nil, instead of :none

Now returns :none and test added to confirm.
Add a function to download a single port as a zip file.

Only works for ports with depth > 0 as Taverna Server does not support the
download of such ports in a zip file individually.

Tests included/updated.
Temporary fix/hack for incorrect interaction feed address.

It should be advertising a full URI but only actually gives a path.
Update Launchy version and make it optional.

Launchy is only used in the t2-run-workflow script so make it optional. New
version doesn't fill the terminal with unwanted output either.
added ssl_version to connection parameters
Put a guard in to check that the SSL version is sensible.

This is checked in before being set in the connection class.
Add SSL version support to the command line tools.

To continue to mirror curl options for the SSL parameters the different SSL
versions can be selected with the same switches: -1, -2 or -3.
Add a new example connection parameter class for SSL version 3.

Simply sets the SSL version to 3.
Describe the connection parameters in more detail.
Merge branch 'ssl-version' into rh/2.4.2

* ssl-version:
  Describe the connection parameters in more detail.
  Add a new example connection parameter class for SSL version 3.
  Add SSL version support to the command line tools.
  Put a guard in to check that the SSL version is sensible.
  added ssl_version to connection parameters
Add Run#error? to check all output ports for errors.

Makes it easy to see at a glance if there are errors in any outputs at all.