feat(init): improve the questions a bit
chore(init): add some todos
feat: simplify loading plugins using patterns like `karma-*`

Now it's possible to load all sybling npm modules through:
plugins = ['karma-*'];

This is also the default configuration.

I hope in most of the cases, people should not have to worry about specifying plugins at all.

This commit also extracts the plugin loading logic into a separate module.
chore(config): add some todos
refactor(init): rely on autoloading the plugins

Do not generate the list of plugins and rather rely on the default config (karma-*).
fix(init): generate correct indentation

This is just a style thing - the generated config file is now correctly indented.
feat(init): generate coffee config files

If the file is *.coffee, generate CoffeeScript config file.
style: add empty lines to config specs
feat(config): add warning if old constants are used

To make upgrading to the new config syntax easier.
fix(logger): configure the logger as soon as possible

This is a tricky problem - we need to show some logs even before parsing the configuration. At that point, we don't know what the logger configuration is.

This sets the reasonable defaults at the very beginning (rather than log4js verbose defaults) and then, sets the user specific settings as soon as possible.
style: make the karma.conf.coffee more coffee-like