The bare skeleton of a custom contact formatting system
Implement Ppl::Format::Custom

This is based on some really neat ideas gleaned from
https://github.com/mark/string_formatter

Thanks Mark!
Implement the first few bits of custom contact formatting
Add a contact ID custom formatter under %i
Process ppl ls output with a custom format if requested
Screw you, extra new line. Get a job.
Add an email address custom formatter
Add a %f format option to email address custom format
Add a phone number custom formatter
Add %10s-style string padding functionality to the custom formatter
Add preset format ability to Ppl::Format::Custom

This is a flagrant violation of the single responsibility principle.
Add --pretty option to ppl ls
Replace "nick --no-color | cut" with custom format in bash completion
Add custom output formatting to ppl email
Switch to %N for contact names because %n is for newlines
Get %n switched over to %N in the tests for Ppl::Format::Custom
Make %n insert a newline in all custom formats
Make %e output the contact's email address
Add %o for outputting contacts' organizations
Add %p for preferred/first phone number