Documentation improvements for jqplot library

I recently used the jqPlot charting library in a project for work, and noticed that one of the documentation files that listed the available options, jqPlotOptions.txt, warned that it was out of date.

I spent about a day going through the jqPlot documentation files cleaning up typos and fixing a few sentences, and filed a pull request.

Then I turned to updating jqPlot options. This is unfortunately fairly difficult because internally the library copies options to instance attributes, but not every attribute is taken from an option. I grepped the code for "opts[.]" and "options[.]", which found a bunch of names, but some seem to be internal only. I filed another pull request with my partial work, but it needs feedback from the jqPlot maintainer to tell if I'm identifying options correctly.

One lesson to take away: always keep your documentation incrementally up to date, instead of just giving up and letting it decay while saying "I'll update it later". Fixing it later is more difficult and probably more error-prone, so over the life of the project delaying documentation updates doesn't save effort. It just lets you be lazy right now.