ezplot: some sanity checking for sorts of inputs we take
ezplot: use inline instead of @ in const double case
ezplot3: sanity checks
ezplot: slightly clearer code with extra variable
ezplot: remove fixme
findsymbols and symvar should do the same thing with one input

its symvar with two inputs, like symvar(f, 2) that does the
"closest to x" thing.  Closes #67.
Merge pull request #161 from cbm755/ezplot_fixes

Ezplot fixes