This configures a directory for posts and downloads all posts on the
authenticated account into the directory, organizing collection posts
into their own subdirectories.

This adds a new parameter that determines whether or not authentication
is required, and also returns an error now.

Closes #16

If you're logged in, now requests will be made with the saved token

Instead of using an INI file for the access token, this stores it and
other user information in a single JSON file.

Adds new `writeas auth` command and saves user's access token to a new
local configuration file.

This closes #10 / T191

This closes #9

This changes the containing dir name to match the fileutils package name.

This simplifies logging and logging/exiting, plus supports the -v flag
for showing verbose output.

A lot has changed to the previously named codegangsta/cli library, and
this gets up to date with everything, fixing issue #8.

It also passes around errors from funcs that perform actions inside the
command funcs, for more Go-ness.

- Adds comments where necessary
- Fixes some variable names
- Fixes if/else statements with returns
- Use fmt.Errorf(...)

When composing posts with `writeas new`, this is checked before `EDITOR`
and then falling back to default editors.