Merge remote-tracking branch 'origin/x2' into develop_integration_2019_w10

cmake_targets/CMakeLists.txt

openair2/COMMON/rrc_messages_def.h

openair2/COMMON/rrc_messages_types.h

openair2/COMMON/x2ap_messages_def.h

openair2/COMMON/x2ap_messages_types.h

openair2/ENB_APP/enb_config.c

openair2/LAYER2/MAC/config.c

openair2/RRC/LTE/rrc_defs.h

openair2/RRC/LTE/rrc_eNB.c

openair2/RRC/LTE/rrc_eNB_S1AP.c

openair2/RRC/LTE/rrc_eNB_S1AP.h

openair2/X2AP/x2ap_eNB.c

openair2/X2AP/x2ap_eNB_decoder.c

openair2/X2AP/x2ap_eNB_defs.h

openair2/X2AP/x2ap_eNB_generate_messages.c

openair2/X2AP/x2ap_eNB_generate_messages.h

openair2/X2AP/x2ap_eNB_handler.c

openair2/X2AP/x2ap_eNB_handler.h

openair2/X2AP/x2ap_eNB_management_procedures.c

openair2/X2AP/x2ap_eNB_management_procedures.h