CLEANUP: assorted typo fixes in the code and comments

This is fifth iteration of typo fixes
diff --git a/contrib/spoa_server/ps_lua.c b/contrib/spoa_server/ps_lua.c
index e7de2d9..2d37d9b 100644
--- a/contrib/spoa_server/ps_lua.c
+++ b/contrib/spoa_server/ps_lua.c
@@ -396,7 +396,7 @@
 		lua_pop(L, 1);
 		return 0;
 	default:
-		fprintf(stderr, "lua unknonwn error: %s\n", lua_tostring(L, 0));
+		fprintf(stderr, "lua unknown error: %s\n", lua_tostring(L, 0));
 		lua_pop(L, 1);
 		return 0;
 	}
@@ -488,7 +488,7 @@
 		case LUA_ERRERR:
 			msg_fmt = msg_fmt ? msg_fmt : "Lua message handler error";
 		default:
-			msg_fmt = msg_fmt ? msg_fmt : "Lua unknonwn error";
+			msg_fmt = msg_fmt ? msg_fmt : "Lua unknown error";
 			msg = lua_tostring(L, -1);
 			if (msg == NULL)
 				msg = "Unknown error";