Use log package instead of hand crafted tracing.
Split glpk-independent code into separate file.
Abstract RI matrix generator as an interface.
Don't call log.Fatal during vbucket map generation.
Fix detection of no improvement termination.
Improve logging of intermediate matrices.
Allow to choose an engine that is used to generate RI.
Implement dummy "rack-unaware" engine.
Decapitalize cli-related messages and errors.