cmake: define USE_OROCOS_RTT flag to indicate that UseOrocos-RTT conventions are in use.

Signed-off-by: Peter Soetens <peter@thesourceworks.com>
deployment: fix error reporting when importing packages

If your package was not using ros, you always got an error.
I upgraded the code to use Rospack directly instead of roslib.

Signed-off-by: Peter Soetens <peter@thesourceworks.com>