* Low impact changes from path_cleanup branch.
This is a step towards minimizing the diff with path_cleanup branch.
* Update ecl.
* Revert matrix update.
* Revert ecl and matrix.
* Update sitl gazebo.
* Revert sitl_gazebo and matrix changes.
The name uart_esc was initially taken by Qualcomm's UART ESC driver but
then got changed into the current mavlink ESC/RC helper. Since the
uart_esc is still around, we should prevent the names clashing.