Enabled enhanced terminal for plotting

Allows using greek letters in plots
Update/reformat rkf45

- Fix a typo in the docstring
- Add more compiler hints
- Update constants to double floats to avoid generic arithmetic
Add more vector operations

(sum) and (standard-deviation)
Add function type declaration to rkf45
Change to double-float value
Add svg terminal to plotting
Make a macro that iterates over matrices and returns result

For some reason, (do-matrix) wasn't expanding when inside a
(with-result) form.  This also puts eveerything inside a loop macro
which feels better even if the macro lambda list is really ugly.

Something to fix later, for sure.
Convert arithmetic to new macro
Add some optimization to (mref)
Clean up lu-decomposition
Speed up matrix multiplication tremendously

fib:   0.0 seconds
parse_int:   0.014 seconds
mandel:   0.001 seconds
quicksort:   0.007 seconds
pi_sum:   0.028 seconds
rand_mat_stat:   2.446 seconds
rand_mat_mul:   2.465 seconds

The rand_matr_mul time before this commit was 912.322 seconds,
representing a speedup of about 370 times.  On my computer this comes
out to about 1.3 times the LAPACK call done by lla. Not too shabby.
Rename (czeros) to (complex-zeros)

I like verbose names to make things easier to read.
Add (make-plane) for initializing matrices

Useful for fractals!
Fix calculation of average of vectors
Export (eps=)

Checks if a number is within machine precision of another.
Speed up random matrix generation and add a complex version

Now, map exports (complex-random-matrix) as well.