rename gsm_subscriber_connection to ran_conn

In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.

* Name choice:

In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.

The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.

* Rationale:

A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.

Also:

- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*

Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
diff --git a/tests/msc_vlr/msc_vlr_test_ms_timeout.c b/tests/msc_vlr/msc_vlr_test_ms_timeout.c
index a4851b3..b09bcee 100644
--- a/tests/msc_vlr/msc_vlr_test_ms_timeout.c
+++ b/tests/msc_vlr/msc_vlr_test_ms_timeout.c
@@ -75,7 +75,7 @@
 	VERBOSE_ASSERT(lu_result_sent, == RES_NONE, "%d");
 	expect_bssap_clear();
 	fake_time_passes(1, 235);
-	btw("SUBSCR_CONN_TIMEOUT has passed, conn is gone.");
+	btw("RAN_CONN_TIMEOUT has passed, conn is gone.");
 	VERBOSE_ASSERT(bssap_clear_sent, == true, "%d");
 	bss_sends_clear_complete();
 	EXPECT_CONN_COUNT(0);
@@ -175,7 +175,7 @@
 	VERBOSE_ASSERT(cm_service_result_sent, == RES_NONE, "%d");
 	expect_bssap_clear();
 	fake_time_passes(1, 235);
-	btw("SUBSCR_CONN_TIMEOUT has passed, conn is gone.");
+	btw("RAN_CONN_TIMEOUT has passed, conn is gone.");
 	VERBOSE_ASSERT(bssap_clear_sent, == true, "%d");
 	bss_sends_clear_complete();
 	EXPECT_CONN_COUNT(0);
@@ -351,7 +351,7 @@
 	VERBOSE_ASSERT(lu_result_sent, == RES_NONE, "%d");
 	expect_bssap_clear();
 	fake_time_passes(1, 235);
-	btw("SUBSCR_CONN_TIMEOUT has passed, conn is gone.");
+	btw("RAN_CONN_TIMEOUT has passed, conn is gone.");
 	VERBOSE_ASSERT(bssap_clear_sent, == true, "%d");
 	bss_sends_clear_complete();
 	EXPECT_CONN_COUNT(0);