Call (private) loggers through namespaced functions

[jleung51]

After some thought, I believe that a better way to expose the loggers publicly is to call namespaced functions, which will call the logger(s) (locked away in an unnamed namespace in exceptional.hpp. This will allow for easier documentation of the methods actually used to log messages, and more reliable usage of the loggers.

[jleung51]

Working on this with the branch namespaced-function-log.

[jleung51]

Completed in this merge commit.