Changes `require` to `require_once`; Refs #6
Refs #14;

*   Renames `model.php` to `adapter/base.php`
*   Renames `db.php` to `dbmanager.php`
*   Changes `require` to `require_once`
Updates documentation for adapters; Refs #14
Throws library specific exception now; Closes #14
modified test files to adopt recent namechanges of files
moved test file of download to http folder
modfied download.php as required
Changed files names according to convention
modified test files to incorporate namechanges
deleted table STATIC_SALT as it was not needed anymore SQL FILE updated
corrected function names in user class
Initial commit of refactoring attempt

Would have been better as a group of smaller commits (but I am lazy ;)
)..

Generally the method contents are omitted as I am trying to get the
interfaces of the objects/classes set down - at this stage, to do this I
do not need to know the contents of the methods (at least, I shouldn't
need to know).