Work when Bundler is not defined [Fixes #3]
Remove 100ms of delay every command :/
Reinstate the global "gem" function [Fixes #5]
Don't debundle twice at the start of each session
Work when source_location doesn't.
I was trying to be clever by requiring the absolute path to rubygems,
but actually it's easier to just rely on the fact that rubygems will be
in the load path.