* tests/gpgscm/tests.scm (absolute-path?): New function.
(canonical-path): Use the new function.
* tests/gpgscm/lib.scm (string-split-pln): New function.
(string-indexp, string-splitp): Likewise.
(string-splitn): Express using the above function.
(string-ltrim, string-rtrim): Fix corner case.
(list->string-reversed): New function.
(read-line): Fix performance.