Added open command to open link in default browser

New 'open' command takes a number argument to open reddit posts in the
users default browser. Needs testing on Windows and Mac OSX. Tested with
Fedora Linux.
Added open command to open link in default browser

New 'open' command takes a number argument to open reddit posts in the
users default browser. Needs testing on Windows and Mac OSX. Tested with
Fedora Linux.
Merge branch 'master' of github.com:robstewart57/hreddit
Use only "start" for opening a URL in Windows