Windows rounding error fixes
Converting float (microns) to int (nanometers, dbu), use the new function:
from SiEPIC.extend import to_itype
to_itype(value, dbu)
e.g.,
from SiEPIC.extend import to_itype
to_itype(12.131, 0.001)
12131
simply dividing by 0.001 doesn't always return the correct answer.