Logging format could be improved

[Pennycook]

There are several inconsistencies in the way that we report warnings and errors. Some are prefixed with information about where (i.e., in which file) an error occurred, some are quite vague, and others are the result of uncaught exceptions. Adopting a consistent format for anything that we log as a warning or error would likely improve usability.

While we're at it, I would also like us to revisit the formatting used by the logger. The current output looks like this:

[INFO   ] An informational message
[WARNING] A warning.
[ERROR  ] Error: An error occurred.

A format like the below would be more consistent with compilers and other command line tools:

An information message.
warning: a warning
error: an error

...especially if we could employ bold and colors to match gcc/clang.