client: Add new osmo-remsim-client-shell binary

This is a remsim-client with an interactive 'shell', where the user
can type in C-APDUs in hex formats, which will be sent to the bankd /
SIM-card.  Responses received from SIM Card via bankd will be printed
in return.

Change-Id: I636505fd9741833ccf5cbd1bcac30f7b9aa94425
diff --git a/src/client/simtrace2-remsim_client.c b/src/client/simtrace2-remsim_client.c
index ce8ea1d..bee8fc9 100644
--- a/src/client/simtrace2-remsim_client.c
+++ b/src/client/simtrace2-remsim_client.c
@@ -94,7 +94,7 @@
 /* global GSMTAP instance */
 static struct gsmtap_inst *g_gti;
 
-static struct bankd_client *g_client;
+struct bankd_client *g_client;
 static void *g_tall_ctx;
 void __thread *talloc_asn1_ctx;
 int asn_debug;