implement subscriber vty interface, tests

Implement VTY commands for subscriber manipulation:
- create / delete subscriber
- modify MSISDN
- add/edit/remove 2G and 3G authentication data
- show by IMSI, MSISDN or DB ID.
(enable/disable CS/PS and purge/unpurge to follow later.)

Implement VTY unit tests for the new commands using new
osmo_verify_transcript_vty.py from osmo-python-tests.

Depends: libosmocore I1e94f5b0717b947d2a7a7d36bacdf04a75cb3522
         osmo-python-tests Id47331009910e651372b9c9c76e12f2e8964cc2c
Change-Id: I42b3b70a0439a8f2e4964d7cc31e593c1f0d7537
diff --git a/src/Makefile.am b/src/Makefile.am
index b410ff3..fc7c653 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,6 +23,7 @@
 	rand.h \
 	ctrl.h \
 	hlr_vty.h \
+	hlr_vty_subscr.h \
 	$(NULL)
 
 bin_PROGRAMS = \
@@ -46,6 +47,7 @@
 	logging.c \
 	rand_urandom.c \
 	hlr_vty.c \
+	hlr_vty_subscr.c \
 	$(NULL)
 
 osmo_hlr_LDADD = \