cmake remove circular linking and reorganize

- px4_add_module now requires MAIN
 - px4_add_library doesn't automatically link

src/lib/CMakeLists.txt

@@ -0,0 +1,50 @@
+############################################################################
+#
+#   Copyright (c) 2017 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_git_submodule(TARGET git_ecl PATH "ecl")
+px4_add_git_submodule(TARGET git_matrix PATH "matrix")
+
+add_subdirectory(battery)
+add_subdirectory(controllib)
+add_subdirectory(conversion)
+add_subdirectory(drivers)
+add_subdirectory(ecl)
+add_subdirectory(FlightTasks)
+add_subdirectory(led)
+add_subdirectory(mathlib)
+add_subdirectory(mixer)
+add_subdirectory(perf)
+add_subdirectory(rc)
+add_subdirectory(terrain_estimation)
+add_subdirectory(tunes)
+add_subdirectory(version)