Integrate version 3 changes

A branch that merges the recent changes on the master branch with libs_refactor to make CPM compatible with the version 3 compilers.

Something to discuss would be how to proceed with the error logging monad. There are currently two approaches (along with naming conventions) taken here:

• The master branch (version 2) uses a stateless ErrorLogger that holds the log entries and a separate ErrorLoggerIO
• The libs_refactor branch (version 3) uses only an effectful ErrorLogger (analogous to ErrorLoggerIO) everywhere. This makes the code slightly more consistent due to fewer fromELM/toELM conversions at the expense of having more liftIOErrorLoggers.

This branch currently largely adopts the latter approach:

master	this branch
ErrorLogger	ErrorLog
ErrorLoggerIO	ErrorLogger
execIO	liftIOErrorLogger
toELM/fromELM	not needed
(|>=), (|>), etc.	(>>=), (>>), etc.