python-orocos-kdl: initial commit (resolves #203)

Note:
Not using "inherit ros", but FILES_${PN}-dev - seems cleaner for a package in recipe-extended (i.e. ros independent). Also, inheriting ros causes errors for orocos-kdl, see https://github.com/bmwcarit/meta-ros/pull/181#commitcomment-4471339
Unfortunately, this also means I cannot refer to ROS_BPN - so "hardcoding" those instead in the FILES directives, and using an expression in kdl.inc. 
I could redefine the ROS_BPN (perhaps using another name) variable in kdl.inc, and use them in the recipes, if this is considered cleaner.