Cygwin Source Code for UCSF Chimera

On Microsoft Windows, chimera uses the Cygwin Linux-like environment to get aggregated programs to run. So in accordance with the Cygwin Licensing Terms, here is a copy of the cygwin1.dll source code. Since the Cygwin source code is updated independently of the chimera distribution and because chimera uses a prebuilt version of cygwin1.dll, the source may correspond to a newer version that what chimera is using.