services: also clear DataFlowInterface in Service::clear()

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: added FILES and DIRECTORY argument types to orocos_install_headers()

Example use cases:
- `orocos_install_headers([FILES] foo.hpp ...)`
   installs header files to `include/orocos/${PROJECT_NAME}/foo.hpp` (FILES is optional)
- `orocos_install_headers(DIRECTORY include/${PROJECT_NAME})`:
   installs all files in `include/${PROJECT_NAME}` to `include/orocos/${PROJECT_NAME}`

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: added INCLUDE_DIRS argument to orocos_generate_package() macro

The INCLUDE_DIRS given will be exported to other catkin and rosbuild packages. They are never installed automatically.
You still have to call orocos_install_headers() to make them available in the install-space.

This mimics catkin's catkin_package(INCLUDE_DIRS ...) macro.

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: fixed orocos_generate_package(DEPENDS_TARGETS ...)

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: use version number from package.xml as default for generated pkg-config files

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
useorocos: silently call catkin_package() from orocos_generate_package()

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Added CleanupFunction to clear the GlobalService before termination

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Copied environment hook from rtt_ros package

This hook is only effective if RTT is installed to a catkin install space.

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Added UNBUFFERED type to ConnPolicy (outgoing streaming connections only)

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Merge branch 'toolchain-2.7'
Merge branch 'unbuffered-connpolicy' of https://github.com/meyerj/rtt into toolchain-2.7
Merge branch 'service-clear-dataflowinterface' of https://github.com/meyerj/rtt into toolchain-2.7
Merge branch 'global-service-cleanup' of https://github.com/meyerj/rtt into toolchain-2.7
Merge branch 'per-package-env-hook' into HEAD