don't use wordexp.h for tilde expansion

wordexp.h is not supported by OpenBSD. Therefore do tilde expansion only
via glob().
rename glob_path() to resolve_tilde() since it should not do globbing.

include/config.h

@@ -126,9 +126,11 @@ struct Config {
 
 /**
  * This function resolves ~ in pathnames.
+ * It may resolve wildcards in the first part of the path, but if no match
+ * or multiple matches are found, it just returns a copy of path as given.
  *
  */
-char *glob_path(const char *path);
+char *resolve_tilde(const char *path);
 
 /**
  * Checks if the given path exists by calling stat().