Now implements (and mostly follows) requirements of Modules/1.1 spec
implementes only the required "secure sandbox" subset of the spec
`module` free variable changed from the `moduleInfo` to an id container
`require` free variable given a "main" property
boot module scope closed and exported
this also changes the interface between boot and bootprefix slightly
(should now be able to create multiple TW instances under node)
BREAKING CHANGES:
The tiddlywiki module itself now exports a single constructor function
Modules which depended on `module` referring to `moduleInfo` will break
Modules which don't conform to Modules/1.1 will break
(by attempting to modify require.main or module.id)
