Standard docs and formats in public_functions.php

Hooray, PHPDoc comments for functions! Also 4-tab coding.

Most functions use the output($arguments, "string") function to print
output, though a few printer-style ones do not yet.
Moved prints to bottom of public_functions

publicPrint functions do not respect the output($arguments, "...") way
of API calls, so they should be separated.
Removed $noverbose from public_functions

Usage of the optional $noverbose=false argument is completely gone.
Initial testing hasn't found any bugs related to it missing.
Moved publicAddBook into publicBookImportISBN

Nothing else was calling publicAddBook, which was basically a redundant
duplicate, so its functionality was moved into publicBookImportISBN.
Added requireArguments function for API

Ensures arguments exist in $arguments for public/API-style functions,
which will be useful for standardizing complaints. Currently only used
in api.php.
Implemented requireArguments for CreateUser

Fixed a glitch with the arrays, too.
Implemented requireArguments in public functions

These now all use the standard mechanism for complaining when a required
argument isn't given.
Added requireUserLogin, requireUserVerification

...to public_functions.php. These are standardized versions of the
login/verification checks that the API functions use.
Implemented requireUserLogin,UserVerification

requireUserLogin and requireqUserVerification are now commonly used in
public_functions.php
Fix for publicFacebookLogin requiring a password

No password should be required for this function.
Fix for cURL request in API not keeping session

This now uses require_once(...) to get the page, instead of making a
complete new request using cURL.

Also some documentation-style fixes.
$_SESSION['salt'] no longer kept

That's insecure, silly.
Fix for slashes in api.php

Lel.
Somewhat standardized API names

The following convention is mostly kept in API functions (see
PHP/public_functions.php for full list):

* User-related functions (add, login, edit) start with publicUser
* Book-related functions (get, import) start with publicBook
Moved password salting into functions

Guh, I can't wait to be secure...
loginAttempt delays slightly, for security

Take that, brute forcing!

...still on SHA256...
Implemented publicUserEditPassword

There's no front-end for it yet, but it works.
API Documentation touchups

Other than allowing 'format' to be in any case for output(), most of the
changes here are in documentation comments.
Merge pull request #105 from Diogenesthecynic/Standardized-API

Standardized API into Master