Must import platform globally since it is used by Target.
Adapt example workflow to new :cores syntax.
Remove :pbs directive completely.
Not parsing duration anyway.
Fix parsing. Shouldn't return a list for :cores and :memory.
Fix subtle bug.

This bug occurs when calling remote() with a cwd which does not exist
on the calling host. Apparently, subprocess checks if the cwd exists
and crashes if not.

This fix remove cwd from the arguments to LocalProcess and thus avoids
the problem.
Assign host directly to task.
Small refactoring to avoid duplicate code.
Add script for running gwf through qsub directly. Fixes #14.