Refactor base class

[jcapriot]

This refactor is aimed at increasing consistency throughout the package, adding a few bits of missing information.

• Gets rid of the ugly set_kwargs funciton.
• Automatically do a check for symmetry and hermitian, if not given.
• Exposes a solve() operation that broadcast's like np.linalg.solve.
• Uses Scipy's triangular solver for Forward and Backward class (and makes them transposes of each other).
• Check's wrapped function signatures for valid keyword arguments.
  • Emits warnings on unused keyword arguments.
• add a solver.transpose() method, which is aliased as a property as solver.T.
• Define's Base as an abstract class, where subclasses must implement a _solver_single and a _solve_multiple.
• Mimic's scipy's more recent rtol and atol keywords for solution checking.