Provide completions based on information retrieved with 'ledger-context-at-point'.
To support step-by-step completion of transactions some more patterns were added
to 'ledger-line-config'. The actual completion rules mostly reuse some of the
convenient input commands that are buried in ledger-mode. Using the standard
pcomplete termination string (" ") to allow a "context switch" at the end of each
completion step.
This is the common convention in Emacs Lisp. Not following it might
cause problems with other packages as functions/variables/macros are
always visible to other modules.
Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
