Commit Victor Liu's suggestion about making the complex division routine more robust

Commit Victor Liu's suggestion about making the complex division routine more robust
tests and builds seems fine.

Message sent on Oct 18th
I just saw a paper on ArXiv about making the complex division routine more robust:
http://arxiv.org/abs/1210.4539
Second author is actually the original inventor of the current algorithm in Lapack.
I have attached my modified DLADIV routine, which passes all the tests in the build process.