_daemon,_reader: return ENOSYS instead of NotImplemented

In _reader we were raising OSError(errno=ENOSYS), but in _dameon
we were raising NotImplementedError. Let's always use ENOSYS.

Also, make the messages in _reader more specific.

Fixes #33.

Author: keszybz

systemd/_daemon.c

@@ -145,14 +145,14 @@ static PyObject* notify(PyObject *self, PyObject *args, PyObject *keywds) {
 #ifdef HAVE_PID_NOTIFY
                 r = sd_pid_notify(pid, unset, msg);
 #else
-                PyErr_SetString(PyExc_NotImplementedError, "Compiled without support for sd_pid_notify");
+                set_error(-ENOSYS, NULL, "Compiled without support for sd_pid_notify");
                 return NULL;
 #endif
         } else {
 #ifdef HAVE_PID_NOTIFY_WITH_FDS
                 r = sd_pid_notify_with_fds(pid, unset, msg, arr, n_fds);
 #else
-                PyErr_SetString(PyExc_NotImplementedError, "Compiled without support for sd_pid_notify_with_fds");
+                set_error(-ENOSYS, NULL, "Compiled without support for sd_pid_notify_with_fds");
                 return NULL;
 #endif
         }

systemd/_reader.c

@@ -1048,7 +1048,7 @@ static PyObject* Reader_enumerate_fields(Reader *self, PyObject *args) {
         _value_set = NULL;
         return value_set;
 #else
-        set_error(-ENOSYS, NULL, "Not implemented");
+        set_error(-ENOSYS, NULL, "Compiled without support for sd_journal_enumerate_fields");
         return NULL;
 #endif
 }
@@ -1069,7 +1069,7 @@ static PyObject* Reader_has_runtime_files(Reader *self, PyObject *args) {
 
         return PyBool_FromLong(r);
 #else
-        set_error(-ENOSYS, NULL, "Not implemented");
+        set_error(-ENOSYS, NULL, "Compiled without support for sd_journal_has_runtime_files");
         return NULL;
 #endif
 }
@@ -1090,7 +1090,7 @@ static PyObject* Reader_has_persistent_files(Reader *self, PyObject *args) {
 
         return PyBool_FromLong(r);
 #else
-        set_error(-ENOSYS, NULL, "Not implemented");
+        set_error(-ENOSYS, NULL, "Compiled without support for sd_journal_has_persistent_files");
         return NULL;
 #endif
 }