BUG onDemand plugin fixture

Added trim() to decodePath function. Headers X-Include-* comes with a
space so some files are loaded twice. Looks like that depends on a
webserver. nginx has the space.
Check if remote class exists in DataObject->getRemoteJoinField()
NEW: Created LessThanOrEqualFilter and GreaterThanEqualFilter
IMPROVEMENT/FEATURE Forcefully write javascripts to the end of the HTML if wanted.
It's defaulted to false. But when set to true, the JS is written to the end of the HTML, even though there are earlier scripts.
This results in faster page-loading if the JS isn't needed earlier-on.
BUG Fixes #2682 - Regression in #2595 causing gridfield headers to break on summary_fields containing field methods
Separate out SS_Query and MySQLQuery from their Database classes

Coding conventions state one class per file (unless it uses an _ to indicate related classes.
Merge pull request #2688 from wilr/spiltclasses

Separate out SS_Query and MySQLQuery from their Database classes
Update form.md

Under the heading ...THE FORM....
 Instantiating a form....
$controller..
  replace and to an.
Merge pull request #2690 from sanjaymundhra/patch-1

Update form.md
Adding test for CheckboxSetField saving into a text DB field.
Merge pull request #2689 from halkyon/checkboxsetfield_test

Adding test for CheckboxSetField saving into a text DB field.
MINOR added onBeforeRender extension hook to FormField
Merge pull request #2692 from sheadawson/formfieldhook

MINOR added onBeforeRender extension hook to FormField
Fixing undefined step caused by change in behat-extensio module.
Fixing broken manage-users behat test.

"ADMIN group" is created by default, but assertions are checking
for "Admin Group".
Update Page-types.md

In the TEMPLATES ....sub-heading..Adding Database Fields ..
     
      IN the line below..
Every time you run db/build to recompile the manifest........

change db/build to dev/build.
Merge pull request #2695 from sanjaymundhra/patch-2

Update Page-types.md
Update secrity.md

The following line is repeated in the section "Don't allow access to .yml files "

See [Apache](/installation/webserver) and [Nginx](/installation/nginx) installation documentation for details 
specific to your web server
Merge pull request #2696 from sanjaymundhra/patch-3

Update secrity.md
Merge pull request #2683 from tractorcow/pulls/2682-fix-gridfieldsortableheader

BUG Fixes #2682 - Regression in #2595