Trim white-space from the start of stderr-logged string from xtrns

... like the last commit that did this, but do in the other 2 places where
stderr output is logged as log messages.
Also, include the extended program name in the stderr log messages, making it
easier to find the output you're looking for.

src/sbbs3/xtrn.cpp

@@ -1673,9 +1673,11 @@ int sbbs_t::external(const char* cmdline, long mode, const char* startup_dir)
 				}
 				if(i > 0) {
 					buf[i] = '\0';
-					truncsp((char*)buf);
-					if(*buf)
-						lprintf(LOG_NOTICE, "%s", buf);
+					p = (char*)buf;
+					truncsp(p);
+					SKIP_WHITESPACE(p);
+					if(*p)
+						lprintf(LOG_NOTICE, "%s: %s", fname, p);
 				}
 
 				/* Eat stderr if mode is EX_BIN */
@@ -1789,7 +1791,7 @@ int sbbs_t::external(const char* cmdline, long mode, const char* startup_dir)
 						truncsp(p);
 						SKIP_WHITESPACE(p);
 						if(*p)
-							lprintf(LOG_NOTICE, "%s", p);
+							lprintf(LOG_NOTICE, "%s: %s", fname, p);
 						i=0;
 						bp=buf;
 					}
@@ -1801,9 +1803,11 @@ int sbbs_t::external(const char* cmdline, long mode, const char* startup_dir)
 			}
 			if(i > 0) {
 				buf[i] = '\0';
-				truncsp((char*)buf);
-				if(*buf)
-					lprintf(LOG_NOTICE, "%s", buf);
+				p = (char*)buf;
+				truncsp(p);
+				SKIP_WHITESPACE(p);
+				if(*p)
+					lprintf(LOG_NOTICE, "%s: %s", fname, p);
 			}
 		}
 	}