initial checkin.

integrating with entity registry for entity
creation and retrieval.
added a clearAll function. Reorganising opening/closing
added schema for componentDef table and component
default.
restructuring
schema property order priorities moved to their
own part of the schema.
syntax fixes
using a backbone model to encapsulate a db statement
- could probably do with generalising
only opening db in initialise - don't yet know if
this is the best policy.
better organisation of query execution
recreation of component tables from def table
updated to work with latest odgnEntity storage.
toSelect can use limit
completed implementation of getEntitiesWithComponents
added getEntity and getEntityComponents
in which the SqlStatement is refactored and is able
to identify attributes which are 'additional'
test entity import
testing that a registry can be brought up with a
pre-existing db.
testing for Schema Component Selects - forming the
basis of entity sets
entitySets created from queries
test for loading components and import