Solve ROSPlan install problems

[ipa-nhg]

@m312z @Morloth1274

squirrel_planning has a dependency with squirrel_planning_system , I need to install the package if I want to setup a continuous integration job for squirrel_planning, and at the moment some headers are missed and I get the following error:

In file included from /opt/ros/indigo/include/rosplan_planning_system/PlanningSystem.h:12:0,
                 from /tmp/squirrel_planning_indigo_prtestbuild/src/squirrel_planning/squirrel_planning_execution/include/squirrel_planning_execution/RPSquirrelRecursion.h:17,
                 from /tmp/squirrel_planning_indigo_prtestbuild/src/squirrel_planning/squirrel_planning_execution/src/RPSquirrelRecursion.cpp:1:
/opt/ros/indigo/include/rosplan_planning_system/PlanningEnvironment.h:9:38: fatal error: ../../src/VALfiles/ptree.h: No such file or directory
 #include "../../src/VALfiles/ptree.h"
                                      ^
compilation terminated.

for further information: KCL-Planning/ROSPlan#16

[m312z]

KCL-Planning/ROSPlan#16 is merged, is this issue solved?