* Changed the Maven target to 1.8
* Performed a preliminary cleanup using IntelliJ's Code Analysis (Only Java 7/8 updates and a few other entries in the Error and Warnings categories)
* Updated the readme to change the required Java version
refactored paheal.net and xbooru.com rippers:
- used absUrl() instead of plain attr()
- album names (and file names for paheal) now passed through filesystemSafe()
