Add in Sys.shlib_list() to list out shared libraries on Linux/OSX
Add in CPU to versioninfo() on mac and linux
Use Sys.cpu_info() instead of my own shelling out silliness
Fix whitespace issue with cpu_summary()
Add Sys.dlpath() to map strings or dlopen handles to absolute pathnames

Currently implemented for OSX and Linux only
Merge pull request #4925 from JuliaLang/sf/debugtools

debugging tools for *nix platforms