I started from tabs that are not on the beginning of lines, and in
several places I did further cleanings.
If you're worried about knowing who wrote some code, for example, if you
get to this commit in "git blame", then note that you can use the "-w"
flag in many git commands to ignore whitespaces. For example, to see
per-line authors, use "git blame -w <file>". Another example: to see
the (*much* smaller) non-whitespace changes in this (or any other)
commit, use "git log -p -w -1 <sha1>".
by moving needed C source to src/plot and building during `make',
but stripping out the copies of gd, png, and zlib; instead, hook
a dc<%>-based back end into plot
