Make this work on Illumos/Solaris

Remove getdomainname and setdomainname as they are not POSIX.

Some system implement sethostname(char *...) instead of const char *.
Since, a passing in const char * will cause an error on those platforms
and passing a char * will not cause an error on any platform, prefer the
latter.
setlogmask: removed global namespace pollution
Merge github.com:postwait/node-posix
removed node.js 0.4 support

Removed the obsolete node.js 0.4 support and added node.js 0.9
and 0.11 to the travis CI configuration.

This release is tagged with a new major version number as
backward compatibility (with node.js v0.4) is broken.