improvements for other consoles and ptys + syntax to run from %USERPROFILE%

Starting from this release, redirections are forced when launching from a pty (they are not when launching from the Windows Console, as usual). To cover the use case described in #11, the callers also try to fallback to the port number saved in ~/.config/cbwin/outbash_port if the OUTBASH_PORT environment variable does not exists. ~/.config/cbwin/outbash_port is set if you launch outbash.exe with --outbash-session as its first param.

A syntax to launch from the %USERPROFILE% directory has also been added - ex: wstart : notepad. This is useful to launch something while in a VolFs cwd in WSL.

To install from the binary archive, copy outbash.exe where you want.

Launch a "Bash on Ubuntu on Windows" session with outbash.exe, and from your unpacked archive directory launch sudo ./install.sh (this will put the WSL wcmd/wstart/wrun commands in /usr/local/bin)

Enjoy!