Email verification step

[dylankeys]

After confirming that the input email is authorised to access the file (functionality already added), send a verification code to the previously input email, once the user receives the email they will either/or:

• Enter the code provided via email into the text box that has appeared in the application, if correct, direct the user to the vault
• Click the verification link in the email that includes the unique verification code, unique file id and user's email and direct the user to the vault, assuming the link contains the relevant data

New database table will be required:
Table name: verification
Columns: id*,user,verificationhash,filehash

From the auth/ page, user/file data will be posted to auth/verify.php where a verification code will be required.