Various updates

This branch has various changes to the functionality and API of the library:

- `Context` now has new properties (that can be referenced in a handler's format string):
    - `#shortDatetime`
    - `#type`
    - `#func`
    - `#filename`
    - `#line`
    - `#column`
- Cleaned up the underlying mechanisms allowing `Dumper` to use color on the console but not elsewhere.
- `BaseHandler` and other handlers now have new methods:
    - `#lessVerbose()`
    - `#moreVerbose()`
    - `#adjustFromArgs()`
- The default format for `ConsoleHandler` has been updated.
- `Logger` has been moved into its own module, and both `Logger` and `Dumper` are now exported by the package.
- `namedLoggers` (an object containing all non-root loggers, keyed by names) is now exported.
- The main `logging` package now has new exports:
    - `logging.getLevelIdx()`
    - `logging.getLevel()`
    - `logging.defaultConsoleHandler`
- The package now has a `.jshintrc`, and has had jshint warnings fixed.

Sorry for not splitting these up more; just haven't really thought about getting them merged and published until we hit the need for continuous integration.