Collective.dancing

---------------------------

- Fix bug where collector sort criteria other than 'created' and
'effective' would result in an error. [nouri]

- Fixed and added test for newsletter preview form. The preview in
the channel page would fail before with ``TypeError: eval() arg 1
must be a string or code object``. [nouri]

--------------------------

- Fix the bug that Doug found where items from collectors would be
rendered fully. [nouri]

- Update installation instructions to account for Plone 3.2.x
buildouts, which are somewhat different. [nouri]

- Added optional keyword argument ``override_vars`` to
Composer.render. ``override_vars`` are now a override individual
``composer_vars`` from e.g. the ``send-newsletter.html`` form.

I've included an example of this in the section "Customizing the
send as newsletter form" in browser.txt (and the new
``send-newsletter-custom-subject.html`` view). This is a pretty
pervasive change since it needs to work with asynchronous sending,
email-previewing, browser-previewing, and with scheduled delivery.

Included is an upgrade step for migrating ``TimedScheduler.items``
to the new format. Refer to the Upgrade_ section for details on how
to run upgrades. [tmog]

--------------------------

- Fix a dependency issue with collective.singing. [nouri]

--------------------------

- We now have much easier installation instructions. [nouri]

- Fix 313044: Don't mess up ``javascript:`` links when making
absolute links out of relative ones. [nouri]

--------------------------

- Fix 318725: Don't mess up ``mailto:`` links when making absolute
links out of relative ones. Thanks to Scribbles. [nouri]

- Exclude all markup with class ``newsletterExclude`` when sending out
mail. This allows for a lo-fi way of marking parts of your template
for exclusion if you can't be bothered to write your own
``IFormatItem``. [nouri]

- Added sort_criteria dict to the collector module. It allows to specify
different query based on the current cue for different sort criteria.
[naro]

--------------------------

- Extended the CVS input of subscribers to allow arbitrary CVS fields
to be stored as part of the subscriptions, and then included in the
composer output using the ``${composervariableFIELDNAME1}``
syntax. [russf]