Import the specified lib or lib.iface into the current environment. This was
inspired by the import command found in Python and acts as a replacement to
the source or . command used in the POSIX shell environment. This
interface searches for the named library in SHLIB_PATH and sources it in.
Thanks to some shell-magic, a given library can only be imported once
(attempting to source the same library in a second time silently returns).
aliases: shlib.import, import