should remove '--no-convert' from arguments, otherwise the output filename will be '--no--convert'
Revert "fixed a bug reported by Matthias Studer: after rm_blank_plot(), res might be an empty list()"

This reverts commit 5a237095aea7215cec6b29d8d2f052a6feb5d9e6.
5a23709 was a careless fix; should still check if sum(figs) > 1 rather than >= 1

merge_low_plot() should do nothing if there are less than 2 plots
add @jtoloe to contributors
take the crap out: no longer supports child concordance
i is no longer in knit_concord
knit() will pass infile and outfile explicitly to concord_gen(), so no need to use default
make sure the input chunk numbers are of the same lengths as output chunks
be careful not to destroy the length of doc, because it is required by concordance
no need to save i in knit_concord (not used any more)
in child mode, output = NULL, so we can use %n% again
change the progress bar symbol to be . instead of > (less intrusive) #395
bump version