Merge pull request #51 from abubeck/hydro_dev

Hydro dev
Merge pull request #53 from abubeck/hydro_dev

Update package.xml
Solved xacro Warning in hydro.
Merge pull request #55 from ipr-sr2/xacro_warning

Solved xacro Warning in hydro.
Merge branch 'hydro_dev' of github.com:ipa320/cob_common into hydro_dev
fixing simulation for hydro. Still wip