Merge pull request #7951 from cladmi/pr/conflicting_module_names

examples/pkgs: rename modules with duplicate names

examples/emcute/Makefile

 # name of your application
-APPLICATION = emcute
+APPLICATION = emcute_example
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native

examples/gcoap/Makefile

 # Default Makefile, for host native GNRC-based networking
 
 # name of your application
-APPLICATION = gcoap
+APPLICATION = gcoap_example
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native

examples/gnrc_tftp/Makefile

 # name of your application
-APPLICATION = gnrc_tftp
+APPLICATION = gnrc_tftp_example
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native

examples/posix_sockets/Makefile

 # name of your application
-APPLICATION = posix_sockets
+APPLICATION = posix_sockets_example
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native

examples/saul/Makefile

 # name of your application
-APPLICATION = saul
+APPLICATION = saul_example
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native