Regular workflows

• More accurate detection of the IO classes in dx:applets.
• Improved handling of WDL constants. For example, multi word
  constants such as ["1", "2", "4"], and 4 + 11 are recognized as
  such. When possible, they are evaluated at compile time.
• Revert default compilation to a regular workflow. It is possible to
  compile to a locked-down workflow by specifying -locked on the
  command line. To specify command workflow inputs from the command line
  use:

dx run foo -i0.N=19