Added new Make target for testing MaxScale's core parts.

This target doesn't need a running MaxScale and only executes core, log_manager and query_classifier unit tests.

cmake/testall.cmake

@@ -0,0 +1,8 @@
+execute_process(COMMAND /bin/sh -c "${CMAKE_BINARY_DIR}/bin/maxscale -c ${CMAKE_BINARY_DIR} &>/dev/null 2> /dev/null > /dev/null")
+execute_process(COMMAND make test RESULT_VARIABLE RVAL)
+execute_process(COMMAND killall maxscale)
+if(NOT RVAL EQUAL 0)
+  message(FATAL_ERROR "Test suite failed with status: ${RVAL}")
+else()
+  message(STATUS "Test exited with status: ${RVAL}")
+endif()