CLEANUP: stream-int: consistently call the si/stream_int functions

As long-time changes have accumulated over time, the exported functions
of the stream-interface were almost all prefixed "si_<something>" while
most private ones (mostly callbacks) were called "stream_int_<something>".
There were still a few confusing exceptions, which were addressed to
follow this shcme :
  - stream_sock_read0(), only used internally, was renamed stream_int_read0()
    and made static
  - stream_int_notify() is only private and was made static
  - stream_int_{check_timeouts,report_error,retnclose,register_handler,update}
    were renamed si_<something>.

Now it is clearer when checking one of these if it risks to be used outside
or not.
diff --git a/src/hlua.c b/src/hlua.c
index 6efabee..a3886cf 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -1638,7 +1638,7 @@
 	 * interface.
 	 */
 	if (!channel_is_empty(si_ic(si)))
-		stream_int_update(si);
+		si_update(si);
 
 	/* If write notifications are registered, we considers we want
 	 * to write, so we clear the blocking flag.
@@ -6564,7 +6564,7 @@
 	/* finished. */
 	case HLUA_E_OK:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons)) {
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 			return 0;
 		}
 		/* If the stack is empty, the function fails. */
@@ -6582,14 +6582,14 @@
 	/* yield. */
 	case HLUA_E_AGAIN:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		SEND_ERR(smp->px, "Lua sample-fetch '%s': cannot use yielded functions.\n", fcn->name);
 		return 0;
 
 	/* finished with error. */
 	case HLUA_E_ERRMSG:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		/* Display log. */
 		SEND_ERR(smp->px, "Lua sample-fetch '%s': %s.\n",
 		         fcn->name, lua_tostring(stream->hlua->T, -1));
@@ -6598,25 +6598,25 @@
 
 	case HLUA_E_ETMOUT:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		SEND_ERR(smp->px, "Lua sample-fetch '%s': execution timeout.\n", fcn->name);
 		return 0;
 
 	case HLUA_E_NOMEM:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		SEND_ERR(smp->px, "Lua sample-fetch '%s': out of memory error.\n", fcn->name);
 		return 0;
 
 	case HLUA_E_YIELD:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		SEND_ERR(smp->px, "Lua sample-fetch '%s': yield not allowed.\n", fcn->name);
 		return 0;
 
 	case HLUA_E_ERR:
 		if (!consistency_check(stream, smp->opt, &stream->hlua->cons))
-			stream_int_retnclose(&stream->si[0], &msg);
+			si_retnclose(&stream->si[0], &msg);
 		/* Display log. */
 		SEND_ERR(smp->px, "Lua sample-fetch '%s' returns an unknown error.\n", fcn->name);
 
@@ -6844,7 +6844,7 @@
 	/* finished. */
 	case HLUA_E_OK:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		if (s->hlua->flags & HLUA_STOP)
@@ -6879,7 +6879,7 @@
 	/* finished with error. */
 	case HLUA_E_ERRMSG:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		/* Display log. */
@@ -6890,7 +6890,7 @@
 
 	case HLUA_E_ETMOUT:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		SEND_ERR(px, "Lua function '%s': execution timeout.\n", rule->arg.hlua_rule->fcn.name);
@@ -6898,7 +6898,7 @@
 
 	case HLUA_E_NOMEM:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		SEND_ERR(px, "Lua function '%s': out of memory error.\n", rule->arg.hlua_rule->fcn.name);
@@ -6906,7 +6906,7 @@
 
 	case HLUA_E_YIELD:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		SEND_ERR(px, "Lua function '%s': aborting Lua processing on expired timeout.\n",
@@ -6915,7 +6915,7 @@
 
 	case HLUA_E_ERR:
 		if (!consistency_check(s, dir, &s->hlua->cons)) {
-			stream_int_retnclose(&s->si[0], &msg);
+			si_retnclose(&s->si[0], &msg);
 			return ACT_RET_ERR;
 		}
 		/* Display log. */