Populate quad solver function. Determine coefficients, report on possible rounding errors, and output results.

Positional arguments removed in main.c.
Example: ./quad_solver -n 1 4.5 1.2E3

GitHub really wants you to put your license in the root directory of the repo. I initially set it to be placed in the documents directory but GitHub automatically changed it to the root directory and I committed it before I noticed, so I am just going to leave it there for now.