Changed sqlite3 from v 2.1.5 to 2.1.7 to successfully compile
Actually 2.1.7 instead of 2.1.x
Added Hook 'beforeValidation' prior to _all_ validations

`beforeValidation` will now be called before the `required` check and before `beforeCreate` and `beforeSave`.  Also the Readme.md file was updated to reflect this addition.
Added Hook 'beforeValidation' prior to _all_ validations

`beforeValidation` will now be called before the `required` check and before `beforeCreate` and `beforeSave`.  Also the Readme.md file was updated to reflect this addition.
Fixed a bug when calling save() on an Instance

Previously, if you called save() on an Instance without passing a callback argument **and** made no changes to the extra variables in that Instance, in the saveInstanceExtra function it assumed the presence of a callback and would throw an error.
Merge pull request #177 from leechfarm/master

Added Hook 'beforeValidation' and updated docs