drop status to experimental
plunger--get-buffer: remove unused NOERASE argument
use cl-copy-list instead of copy-list
add plunger-pull-file

This merges and replaces the old plunger-import and
plunger-import-single functions.
move plunger-pull-file into plunger.el

remove plunger-import.el
bump to 0.2.2