Documentation errata for 3.0.7
Merge pull request #3627 from evildmp/user-docs

Documentation errata for 3.0.7
Backported #3416
Remove reference to treebeard, use mptt, we're on 3.0.x
Merge pull request #3629 from yakky/fix_docs

Remove reference to treebeard, use mptt, we're on 3.0.x
Added require_parent to config options for CMS_PLACEHOLDER_CONF
Merge pull request #3628 from jrief/backport-issue-3416

Backported #3416
Fixed a typo.
Fixed a typo.
Merge pull request #3635 from mooja/patch-3

Fixed a typo.
Merge pull request #3633 from mooja/patch-1

Fixed a typo.
Fixed class name.

The plugin app we created earlier in the tutorial was 'polls_plugin', not
djangocms_polls.
Added code blocks

Without the :: the following indented text isn't viewed as a code block in
html documentation.
Merge pull request #3638 from evildmp/mooja

Fixed class name.
Merge pull request #3639 from evildmp/patch-2

Added code blocks
Notes on using technical terms
bugfix: bad tooltips and structure board areas positions

When the sideframe is opened, tooltips and structure board areas are
badly moved to the right.

As tooltips and area are "css positioned" and jquery offset function is
relative to the document (not the first relative/absolute parent), we
need to substract first relative/absolute parent offset.
Merge pull request #3649 from webu/bugfix/structureboard_areas_and_tooltips_position

bugfix: bad tooltips and structure board areas positions
fixed documentation of Django requirements for 3.0.x
Merge pull request #3652 from ojii/support/3.0.x

fixed documentation of Django requirements for 3.0.x