rename the JaySchema class to Validator
top-level module that exposes the rest of the library
rename internal usage of `new JaySchema` to `new JaySchema.Validator`
rename jayschema.js to jaySchema.js
use the public Errors object in the HTTP loader
rename JaySchema.HttpLoader to JaySchema.Loaders.Http
update README.md to reflect new API
rename httpLoader tests to match the module filename
avoid a circular require reference that causes problems with v0.1.x compatibility
use the correct API to get to the HTTP loader for testing
modify the new API to retain v0.1.x compatibility

Will be deprecated in a future major release, e.g. 0.3.x or 0.4.x.
update for renamed jaySchema.js module
add 0.1.x compatibility note to README.md
Merge branch 'export-multiple-objects' into develop