parameter manager: factor out rosparam array loading, style cleanup
graft sensors: style cleanup
Merge pull request #21 from mikeferguson/hydro-devel

Clean up style of parameter manager
Inintialize covariances in topics

On my system, I was seeing cases where the UKF diverged about 50% of the
time during the first updated, because the override covariances aren't
initialized, and would occasionally have values like 1.48947e+195