Add Contingent-FF planner node

[dgerod]

Existing FF planner node is not working with Contingent-FF, reason is explained in #254 and #255 issues. This pull request fixes these issues by creating an specific node for Contingent-FF.

[bilal9876]

when I try to generate a contingent plan using contingent-ff the generated plan is empty.

the problem occurs only if the domain file contains a "fluents" keyword.

/home/bilal/rosplan_catkin_ws/src/rosplan/rosplan_planning_system/test/pddl/turtlebot/domain.pddl: syntax error in line 3, ':FLUENTS': domain definition expected

ERROR: service [/rosplan_planner_interface/planning_server] responded with an error:

also the same for DURATIVE-ACTIONS

syntax error in line 3, ':DURATIVE-ACTIONS':

[dgerod]

@bilal9876 Did you try to execute your plan using directly Contingent-FF binary? For your explanation it seems a kind of planner issue but not node one, do you agree?

[bilal9876]

yes for sure. I execute the compiled version of contingent-ff from the bin directory directly using command prompt and it is generated plan successfully if the domain file does not contain keywords like durative-action or fluents.

[dgerod]

OK, thanks your clarification. So, this is an issue of the Contingent-FF planner itself.