Added YouTube API to the framework.

This commit includes the addition of the youtube API to the app, as well
as a custom javascript file called "karaoke.js".
Added index.php page and wireframe PDF

This commit added new files, most importantly the index.php page and the
wireframe structure of the app.  There are also changes to the custom
"karaoke.js" file and the "youtube.js" file.
Added new php pages and files

In this commit, I include the "sanitize.php" file and the
"add_video.php" page.
Added new php Object classes

I added new PHP Object Classes to handle operations in querying the
database.
Added initialisation file.

This is a new initialisation file for querying the database.
Changed parameter for "video_id" field
Made changes to 3 php files

Modified "validate.php", "video.php", and "add_video.php".  Video entry
creation now possible, including error reporting.
Updated the "validate.php" class

Now, the "validate.php" class has more orderly manner of echoing errors.
Added "update_video.php" file

I added the "update_video.php" file so that the details of the video
entries can be edited by a logged in user.
Added "delete_video.php" file, modified JS

I added a new delete_video.php file for the CRUD operations on the
queries, and I also modified some functions in the "Video.php" class and
"karaoke.js" file.
Added new files for user CRUD

I added new php files and php classes for enabling of CRUD for
users/admins.
Deleted public folder

Deleted the public folder which used to have php files.
Added new custom.js file and user permissions

I created a new "karaoke.admin.js" file and added key permissions in
registering users.
Added nl2br method in textarea inputs
Modified video-CRUD responses
Made changes: index.php and manage_users.php
Added new user management files

New files for user management are: "users_processing.php" and
"manage_users.js".  The previous "register.php" has now become
"manage_users.php".
Deleted one file

The former "register.php" file for user CRUD is now discarded.
Added new user CRUD functionality

I modified sections of the 6 committed files.  I deleted the old
"index.html" file.  I added an "edit_user_details.php" file.  I also
streamlined the confirmation for user logged in status.
Added new Administrator abilities

Administrator now has a more flexible interface to manage site users
with "manage_users.php" and "manage_users.js".