Adding tests for linear algebra functions

Additionally, fixed a small bug that prevented .dot() and .angle() from
being called on a jStat object, as opposed to as a static function.

There are still untested functions in the linear algebra library,
and it does not make sense that all of the linear algebra functions
can be called on a jStat() object but only accept plain matricies
as arguments. This future change will be made easier with fuller test
coverage.

Fixed tabs to spaces, including on the template.js test template file. 

Additionally, a small change on the studentt inv test got into this PR -
but I believe the negative value is correct, per R's qt(0.2, 10).

(Tests pass on my machine 205/205). 
style: `if (typeof ...`.