Major Update.

In some objects You can apply object-related methods.

Status:

• Album object supported.
• Artist object supported.
• Tag object supported. (TagMethods.getTopTags not supported because is useless, no Tag attribute used)
• Track object supported.
• User object supported.

Dev Changelog:

• Add capability of applying UserMethods in User.
• Created example-related. Watch them on ./example.
• Fixed clean.sh.
• Added .g.dart to make possible the usage from git in pubspec.yaml
• Updated the README.md for Major Update.
• Updated the CHANGELOG.md. This thing You're reading right now
• Fix Artists in Tracks gained from user.getRecentTracks().