Additional improvement to CommonJS Modules support
 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)