3PAR showpatch CLI command in the hp3parclient

Added 2 HP3ParClient methods which
evoke the 3PAR CLI "showpatch" command.

1. getPatch(self, patch_id):

   Equivalent to "showpatch -d <patch_id>".

   Output is returned as a list of strings.
   Each string contains one line of raw output
   from the CLI.

2. getPatches(self, history=True)

   Equivalent to "showpatch [-hist]".

   If the history parameter is true (default) then
   the -hist option is added.

   The CLI output describes headers and data.  This
   method returns the output as a collection with
   total and members.  'total' is the number of members.
   'members' is a list of dictionaries.  Each dictionary
   represents one line of data using the headers as
   the keys and the parsed data row as the corresponding
   values.

   If the CLI does not return a header and data then
   total will be zero and members will be an empty list.

Change-Id: I0b83219425a73bfa9698b7626d5fcee58ffeeb69