Adding a couple new functions to Association that will help implement
associations saving
Skeleton code for saving associations
Adding stub save() implementations to all associations
Implemented saving belongsTo association
Added test to prove that valiadtion in associated save will abort the
full save operation
Implemented save for hasOne
Implemented saving hasMany associations and making sure some changes
made to the entity are rolled back if saving fails
Adding test for saving hasMany and atomic set to false
Not aborting main saving operation if atomic is false and an association
fails saving
Only trying to save associatiations if they are marked
as dirty
Reading primary key from schema and a little work towards supporting
tables with no primary key
Implemented BelongsToMany saving
Implementing handling of non atomic saves for BelongsToMany
Test methods for saving belongsToMany with validation errors in the
joint entities
Adding docs for saving functions in belongsToMany
Making Entity::dirty() able to tell if the entity itself is dirty
Don't save entities that haven't changed since last time they were
persisted
Making it possible to append additional links to a belongsToMany, this
assumes that joint information is present
Added ability to control how deeps associations can be saved and what
options are passed to each level
Adding api docs for some methods