Mangle the PCGM tests, commit something that just might work even when we fail to converge.
Use the infinity norm in the PCGM tests.
Test our (P)CGM implementation against Octave's.
Fix up preconditioned CGM code. Rename 'A' to 'Q' in preconditioned CGM code. Test the preconditioned CGM against the simple implementation.
Add the first working version of the preconditioned CGM.