Release Name: 0.7.4

Notes:
This is basically the beta for 0.8.0. Big changes in this release include
renames of certain classes, and lots of code shedding into smaller external 
libraries. And, as always, lots more syntactical sugar.


Changes:
* WARNING: changed various field class names to be more Ruby-ish: TextField to
  StringField, LinkField to DomainObjectField, DecimalField to FloatField, and 
	SubsetLinkField to SubsetDomainObjectField
* WARNING: extracted QueueHash, Ruby Month, USCommerce, English Extensions, and 
  ContextualService into separate libraries
* Fixed MockObjectStore#get_max
* Fixed a bug where a DomainObjectProxy couldn't get the value of the newly 
  committed dobj inside of the post_commit_trigger
* @original_values hash available inside of DomainObject, for use in triggers
* Query::In works for text fields, too
* added MockDbBridge#set_next_pk_id; this is needed for DomainMock
* DomainObject#get also dispatches to ObjectStore#get_filtered
* you can set a default_setup_hash for a domain class' fields
* DomainObject handles one-line field definitions in plural form: 'booleans', 
  'texts', etc.
* added DomainObject.exist?
* added DomainObject#delete! and #update! 
* Fixed English.plural with 'axis' and 'datum'
* added nil? operators in query inference 
* Global methods won't interfere with DomainObject methods
* DomainObject's one-liners only create fields once