FIX Properly show link for showing and hiding class spec in model admin
Clarified DataList->limit() docs
Impossible to unselect TreeDropdownField

It was impossible to unselect TreeDropdownField.
'!' operator should not be used at all and identical comparison (===) was too "strict" (self.getValue() returns string but $(node).data('id') returns number).
Merge pull request #1099 from uniun/patch-4

Impossible to unselect TreeDropdownField
Merge pull request #1098 from patbolo/fix/model-admin-spec

FIX #8188 Properly show link for showing and hiding class spec in model admin
BUG Don't double unescape URLs in history.js (fixes #8170)

Merged in pull request https://github.com/balupton/history.js/pull/108.
This has been a serious problem with the library for more than a year,
see https://github.com/balupton/history.js/issues/228.
BUG Regression in Form->clearMessage() (fixes #8186)

See 729bcc9
BUG PaginatedList deprecated method was calling non-existent method
Merge pull request #1102 from jthomerson/fix_paginatedlist_settotalitems

BUG PaginatedList deprecated method was calling non-existent method
Wider sidebar to accommodate "add" and "edit" buttons

Conflicts:
	admin/css/screen.css
Wider side panel to fit "add" and "edit" button

Moved "edit tree" button into same DOM structure so
we can layout them more easily through inline-block.

Conflicts:
	admin/css/screen.css
	admin/scss/_style.scss
BUG Permission checkbox display on members (fixes #8193)
FIX: Escape the -f argument passed to mail()
Update admin/code/ModelAdmin.php

Changed "Clear Database before import" - which is incorrect (not the whole database gets wiped, only the data in the model at hand) with the simpler: "replace data".
Merge pull request #1110 from sunnysideup/patch-9

Update admin/code/ModelAdmin.php
Update docs/en/reference/form-field-types.md