Check error handlers for specific classes first

This allows adding error handlers like this:

    @app.errorhandler(werkzeug.exceptions.Forbidden)

And subclassing HTTPExceptions:

    class ForbiddenBecauseReason(Forbidden): pass

    @app.errorhandler(ForbiddenBecauseReason)
    def error1(): return "Forbidden because reason", 403
    @app.errorhandler(403)
    def error2(): return "Forbidden", 403

... the idea being, that a flask extension might want to raise an
exception, with the default behaviour of creating a HTTP error page,
but still allowing the user to add a view/handler specific to that
exception (e.g., "Forbidden because you are not in the right group").
Fix import in viewdecorators.rst for @templated
Tweak wording in viewdecorators.rst
Fix typos in docstrings and comments in run.py
few mispelling errors
Merge pull request #1032 from cgar/spelling

few mispelling errors
Merge pull request #1030 from zakj/master

Fix typos in docstrings and comments in run.py
Depend on click now
Added click support to Flask
Added changelog entry for click
Updated docs for click support
Merge branch 'master' of github.com:mitsuhiko/flask
Added missing documentation page
Added a missing docstring
Add "." to sys.path by default
Updated tutorial to the flask script
Fix a docstring type in cli.py.
Merge pull request #1039 from erikrose/patch-1

Fix a docstring type in cli.py.
Updated documentation once more for new cli.
Merge branch 'master' of github.com:mitsuhiko/flask