Add command handling tests, resolve bugs

Jan Breuer

2015-04-14 781ef98e5441bf6aa12c50657bf2161953a79858

 libscpi/src/units.c

@@ -112,6 +112,7 @@
    {/* name */ "NAN", /* type */ SCPI_NUM_NAN},
    {/* name */ "INFinity", /* type */ SCPI_NUM_INF},
    {/* name */ "NINF", /* type */ SCPI_NUM_NINF},
    {/* name */ "AUTO", /* type */ SCPI_NUM_AUTO},
    SCPI_CHOICE_LIST_END,
};