Install as Bash func to avoid loading a file each prompt

This also moves the configuration to your .bashrc file.
Documentation update
Update README.md
Handle missing __git_ps1 gracefully
Handle missing __git_ps1 even more gracefully
Merge branch 'rc-config' of github.com:superjer/bashline into rc-config
Handle missing __git_sp1 with sublime grace
Powerline symbols off by default

Use bashline_powerline_font=on to enable.
Merge branch 'rc-config' of superjer.com:bashline into rc-config