Add rcl_action package and headers (#307)

* Create rcl_action package with proposed headers for:
  - Action client
  - Action server
  - Goal handle
  - Goal state machine
  - Types

* Add rcl_action.h and Doxyfile

* Add functions for adding action clients and action servers to a wait set

* Add default QoS profile for status topic and document default options for action clients/servers

* Include all headers in a .c file for testing compilation

rcl_action/Doxyfile

@@ -0,0 +1,32 @@
+# All settings not listed here will use the Doxygen default values.
+
+PROJECT_NAME           = "rcl_action"
+PROJECT_NUMBER         = master
+PROJECT_BRIEF          = "C API providing common functionality for ROS actions."
+
+INPUT                  = ./include
+RECURSIVE              = YES
+OUTPUT_DIRECTORY       = doc_output
+
+EXTRACT_ALL            = YES
+SORT_MEMBER_DOCS       = NO
+
+GENERATE_LATEX         = NO
+
+ENABLE_PREPROCESSING   = YES
+MACRO_EXPANSION        = YES
+EXPAND_ONLY_PREDEF     = YES
+PREDEFINED             += RCL_PUBLIC=
+PREDEFINED             += RCL_WARN_UNUSED=
+
+# Uncomment to generate internal documentation.
+ENABLED_SECTIONS       = INTERNAL
+INPUT                  += ./src/rcl/arguments.c
+
+# Tag files that do not exist will produce a warning and cross-project linking will not work.
+TAGFILES += "../../../../doxygen_tag_files/cppreference-doxygen-web.tag.xml=http://en.cppreference.com/w/"
+# Consider changing "latest" to the version you want to reference (e.g. beta1 or 1.0.0)
+TAGFILES += "../../../../doxygen_tag_files/rmw.tag=http://docs.ros2.org/latest/api/rmw/"
+TAGFILES += "../../../../doxygen_tag_files/rcutils.tag=http://docs.ros2.org/latest/api/rcutils/"
+# Uncomment to generate tag files for cross-project linking.
+#GENERATE_TAGFILE = "../../../../doxygen_tag_files/rcl.tag"