Cleaned up and improved functionality

Added some FreeBSD/Linux specific handling of
id -un/whoami command in .bashrc prompt setting.
Handled vless alias to locate less.vim macro
either in /usr/share or /usr/local/share.
Cleaned up M4_HOSTNAME with an M4 regex that only uses 1 line.
Added M4_OS to get the OS name (FreeBSD or Linux).
Organized and added some smarts to .bash_aliases.