Added two action servers for public engagements deployments.

1. emulates camera sound a a flash using the robot hardware for taking pictures
2. detects intruders by listening to the people perception topics.
Merge pull request #97 from cdondrup/hydro-devel

Added two action servers for public engagement deployments.
added costmap flag to service
Merge branch 'hydro-devel' of https://github.com/strands-project/strands_utils into hydro-devel
explained usage of arguments 'map' and 'is_costmap'
Update README.md
Merge branch 'master' of https://github.com/kunzel/strands_utils into hydro-devel
changed parameter name back to map_frame
Added distance from pose calculation script.
Added nav stat distance calc.
Added correct empty response.
Merge pull request #100 from hawesie/hydro-devel

Scripts for calculating distance travelled.
Merge pull request #99 from kunzel/hydro-devel

Added mode for generating poses on costmaps
Merge branch 'hydro-devel' of https://github.com/strands-project/strands_utils into hydro-devel
updating fork with multiple changes