Use FOO_VERSION variables to detect shells

Kludging around with ps is awkward and platform specific (Old
implemntation throws errors on osx)
Merge pull request #8 from richo/features/sane_shell_tests

Use FOO_VERSION variables to detect shells
Use a quoted heredoc to show the logo as it'll render

Allows those of us with rampant OCD to scroll past it without
doubletaking.
Merge pull request #9 from richo/features/ocd_logo

Use a quoted heredoc to show the logo as it'll render