Merge branch 'mbedtls-1.3' into development

* mbedtls-1.3:
  Mark unused constant as such
  Update ChangeLog for recent external bugfix
  Serious bug fix in entropy.c
  Fix memleak with repeated [gc]cm_setkey()
  fix minor bug in path_cnt checks

Conflicts:
	include/mbedtls/cipher.h
	library/ccm.c
	library/entropy.c
	library/gcm.c
	library/x509_crt.c