initial commit

basic infrastructure
added testing infrastructure
added README

including symlink to appease GitHub
added front page and user registration

templates symlink required for local development
added login test

that's essentially just testing TiddlyWeb core functionality, but seems
a relevant part of the story
added auto-login upon registration
added user dashboard handler

no actual contents yet
refactored auth handling in tests

for readability
integrated logout functionality

just a thin wrapper around tiddlywebplugins.logout
added Travis CI configuration

for independent confirmation across different Python versions and in
isolated environments (e.g. ensuring there's no `tiddlywebconfig.py`
interference)
dropped Python 2.5 support

it appears there are issues with Jinja2:
https://travis-ci.org/FND/tiddlywebplugins.bfw/jobs/7491098

    E File ".../python2.5/site-packages/jinja2/environment.py", line 648
    E info.external_attr = 0o755 << 16
    E ^
    E SyntaxError: invalid syntax
created FriendlyError middleware

this provides the infrastructure for presenting errors as HTML pages
within the regular layout

caveats:
* doesn't work for 404/405 yet because (annoyingly) Selector's error
  handling takes precedence
* should probably only kick in for 'Accept: text/html'?
* the actual error messages are not very friendly
* there's not much layout and no styling so far, so it's barely
  distinguishable from plain text for now
* various minor issues/uncertainties; see inline comments
simplified FriendlyError status handling

we're only operating on `HTTPException`s here, so it's safe to rely on
the `status` semantics
extended friendly error handling to 404s and 405s

unfortunately, this is a bit awkward (note the inline comment)
moved initialization logic to separate module

this avoids import weirdness while keeping `__init__.py` free of logic
(so things like `setup.py` can use its metadata without worrying about
side-effects or circular imports)
simplified redirection handling

thanks to @cdent for the pointer
renamed provision category

as suggested by @cdent, this is actually what we're going for

still no functionality for this yet though
implemented infrastructure for wiki creation

no UI yet though
simplified policy check

as pointed out by @cdent, `usersign` already contains all the necessary
information
fixed handling of non-private wiki creation