Added pitch control and the ldtravo heading model without the ramp control.
Merge branch 'ldtravocean_branch_v2' of https://github.com/labust/labust-ros-pkg into ldtravocean_branch_v2
Merge branch 'ldtravocean_branch_v2' of https://github.com/labust/labust-ros-pkg into ldtravocean_branch_v2
Changes to the altitude controller.