Factor variables cause multiple issues

[bryce-carson]

When the MLR module is using imported data with factors, factor variables seem to cause a couple issues:

• A number is appended to the name of the factor variable within the linear model summary output (Gender2 in the case of the hepatic systolic pressure example)
• The factor variable is not found by name when it is bound in the environment by with(), causing MathJax-rendered outputs to fail with an error

@ashokkrish, see this new issue tracking the bug caused by properly interpreted factor variables. It is not directly related to #53.

[bryce-carson]

[bryce-carson]

Causes

1. model renames the factor variable, appending the level (or label) to the name of the factor variable.

That carries onward to coef and summary and everything else, and is responsible for breaking my mget code which is used to construct the LateX regression equations and everything else.