Merge pull request #2067 from chillu/pulls/sqlquery-zero-limit

BUG Accept $limit=0 in SQLQuery->setLimit()
 Ensure Cookie::get() will immediately return results.

Without this change, a call to Cookie::get() immediately after Cookie::set()
won't return the value provided.  This creates some unintuitive edge-cases,
although to date it looks like they have been worked around.

The patch doesn't have a test because our testing framework doesn't deal
with cookies well.
Merge pull request #2068 from sminnee/cookie-fix

 Ensure Cookie::get() will immediately return results.
MINOR: equality check consistency

Updated all equality logic checks to use double == for consistency across the page.
MINOR: equality check consistency

Updated all equality checks to use double equals (==) for consistency.
API Removed user_error when setting missing option on UploadField via setConfig. Added documentation to this function as a replacement for the check.
BUG Fixed dropdown step definition for "preview" dropdowns

Broke after I optimized it to work with a TreeDropdownField
which assumes <li><a> structures that thie "preview" dropdowns
don't have. I also failed at the recursion assignment, causing
infinite loops...
Behat: Adding context for 'Given I should not see a "xxx" button'
Limit "should see a button" to actually visible elements
Less assumptions in "HTML field contains" step

Not using the loose idea of a "field name" in the NamedSelector
sense of the word as "field with id exists".
Behat: More robust "field should contain" logic
Behat: "Insert image from web" feature

Partially fixes https://github.com/silverstripe/silverstripe-cms/issues/628
Modified a bit by Ingo :)
Merge pull request #2071 from tractorcow/3.1-uploadfield-tweaks

API Removed user_error  UploadField::setConfig
Merge pull request #2070 from stevie-mayhew/patch-2

MINOR: equality check consistency
Merge pull request #2069 from stevie-mayhew/patch-1

MINOR: equality check consistency
Merge pull request #2063 from g4b0/mysqldatabase-extensible

Enhancement: replaced private with protected
Adding passwordless message instead of throwing an exception
Merge pull request #2057 from jthomerson/enhancement_3.1_do_not_run_abstract_test_cases

ENHANCEMENT: Do not attempt to run abstract test classes
Allow PasswordValidator to be translated
Merge pull request #2076 from halkyon/passwordvalidator_translate

Allow PasswordValidator to be translated