error whenever there are no DRC-CIF rules in the techfile. The
same error will be raised anyway when reading the techfile if
DRC-CIF rules are declared without a style being specified.
reduction of memory and startup time, which was to maintain only
one CIF style in memory. The new method is just to read in and
keep the DRC CIF style separately from the output CIF style.
Because the CIF sections of the techfile are read before the DRC
sections, and the CIF DRC style is declared in the DRC section,
the CIF DRC style is read in on the fly during the first DRC
checking.