#27 Support for OpenSolaris

[Neale Ferguson]

The following set of diffs was used to get trousers building cleanly on openSolaris. I note the use of #ifdef SOLARIS in the code already but not all these result in a clean build. I've used the __sun preprocessor tag instead of just relying of SOLARIS. I've left the existing SOLARIS stuff intact just in case there was another reason for it being there.

[Neale Ferguson]

Diffs used to get clean build on OpenSolaris