useorocos: always set cmake library, runtime and archive output directories according to the build-tool in use

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: do not set cmake output directories to CMAKE_CURRENT_BINARY_DIR for plain cmake builds as this breaks ocl

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: readded Eclipse project workaround with a cmake warning

See discussion on https://github.com/orocos-toolchain/rtt/pull/12 for details.
rosbuild users should really set their output paths explicitly before including UseOROCOS-RTT.cmake.

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
deployment/plugin: remove duplicates from component/plugin search paths

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: disable caching of pkg-config contents for orocos_find_package()

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>