Added service to enable and disable tool contact

[URJala]

Also added service to get robot software version.

[URJala]

This requires changes from PR.
This implements the feature requested in #897

[URJala]

Split this pull request into two. This PR now only implements the tool contact functionality and testing of that (Will only work on E-series robots). The get_version service implementation has been moved to PR.

[fmauch]

I've tested this today and while it seems to be working well, I think the interface should be improved:

• The functionality should go to its own controller
• The controller should be implemented as a chainable controller such that
  • It can be chained after a passthrough trajectory controller (see Forward trajectory controller #944)
  • When chained activating tool contact detection should be done automatically
  • Tool contact should be acknowledged automatically when the trajectory finished
• When used standalone it should provide an action.