remove old logger (sorry Jon)
first stab at a logger
add method type to proc, and align columns
add docstrings and rework mutex
replace msg string with fmt.Sprint(...)
add Debug method and exclude it by default
behave more like the standard logger
add log field to participant+engine+state
initialize logger and use it in interpreter
replace panics with logs, where possible
use Sprintln to add spaces between args
better traces during testing
handle empty quorum error properly
add siaerror
remove error field from siaerror
add context errors
Merge pull request #231 from lukechampine/logger

Fixes #226
Merge branch 'master' into papers
finish non-scaling solution