Moving the screenshot to the assets directory

Related #89
updating the javascript to include more whitespace as per the wordpress javascript coding standards
adding a 'GitHub Plugin URI' to the wordpress-plugin header

Fixes #75
defining a section to provide links for recommended tools
Update README.txt

Add additional possible installation methods
adding a 'TODO' so users can more easily find where all they need to supply the name of their plugin

Fixes #91
Removing a lot of whitespace, updating function comments, and comment blocks within a function, and making sure no comments exceed 80 characters
removing extraneous whitespace, making sure comment lines don't exceed 80 characters, and providing updated comment blocks for functions, inline comments, and documentation for the new admin class
removing extraneous whitespace, making sure comment lines don't exceed 80 characters, and providing updated comment blocks for functions, inline comments, and documentation for the new admin class
adding whitespace between the header and the markup
removing the scope qualifier on the constant
updating the read me to include the new features of the boilerplate
updating the change log with everything that's going into 3.0.0
including more information about the github updater

fixes #75
Update plugin-name.pot
updating the references to the languages directory as per @grappler's original implementation
Update README.md

This is not valid any more
Update class-plugin-name-admin.php