Bumping version number to 0.5.dev1

Updating version compatibility function to include "dev" version policy.
Added a section stub on version numbers.
Changing version number schema to match semver; redoing tangelo.requireCompatibleVersion().
Committing todo conf change for duration of editing branch.
Removing tangelo.appendFunction()
Dumped tangelo.allDefined()
Fixed logic error in testing for presence of jQuery
Changing "tangelo.defaults()" to "tangelo.config()"

Closes #254
Dumping tangelo.identity()
Moved non-core functions into util.js
Melded tangelo.legal_path() and tangelo.abspath() into single, better function

Closes #252
Merge branch 'reorganize-js'
Updated docs for legal_path (now called abspath)
Merge branch 'docs'

Merging beefed up documentation into master so that documentation can properly
reflect some structural changes made on master in the meantime.