Implement more Plotting Options via Pyplot API

[mepcotterell]

Both ::plotv and ::plotm use the matplotlib.pyplot module to build there plots. As this module has support many different kinds of plots, the ::plotv and ::plotm commands should be extended to provide more plot types.

Some plot types of interest include:

• acorr
• bar
• boxplot
• scatter
• xkcd

The plot types above will likely be revised over the lifetime of this issue.

[DatabaseDat]

Will look into adding bar graphs to ::plotv