Fix: Make CSSContentParser's use of 'Tidy' consistent
Merge pull request #3401 from kinglozzer/pulls/fix-cli-tidy

Fix CSSContentParser's use of CLI 'Tidy'
Update urlvariabletools.md

Remove strange reference to flush values in showtemplate line.
CSSContentParser: Fix mispelled "tidy" and correct case of "tidy" class
Merge pull request #3416 from halkyon/tidy_doc

CSSContentParser: Fix mispelled "tidy" and correct case of "tidy" class
Remove suppression operator on session_start()

This was originally added to stop PHP on Windows complaining that it
couldn't garbage collect old sessions, but that was for an old version
of PHP years ago and doesn't seem to be an issue any longer. We
really shouldn't be suppressing this. If session_start() threw a
warning that it couldn't write to the filesystem, then we wouldn't
know about it at all.
DOCS: correct notes on TEMP_FOLDER

getTempParentFolder() in framewor/core/TempPath.php checks for silverstripe-cache directory in webroot first, failing that it falls back on the sys_get_temp_dir() folder.

also, getTempFolder() is no longer in framework/core/Core.php since #b075fa29c59f970bea31bbe8be1bd6560a8778b6, it is now located in framework/core/TempPath.php
NEW Provide a consistent way of triggering flush

Provides an interface for classes to implement their own flush()
functionality. This function gets called early in a request on
all implementations of Flushable when flush=1|all is requested in the
URL.

This fix came out of an issue where Requirements combined files were not
being cleaned up after dev/build?flush=1, due to the fact that flush
would only occur when you called it while on a page that used those
combined files, but not in any other contexts. This will now call flush
on any implementors of Flushable regardless of the context of where
flush was called.
Merge pull request #3421 from christopherdarling/patch-1

DOCS: correct notes on TEMP_FOLDER
Merge pull request #3393 from halkyon/flushable

NEW Provide a consistent way of triggering flush
Fixing HHVM builds not having tidy support built-in to PHP (#3414)

Installs cli tidy, which is used as a fallback for CSSContentParser.
Merge pull request #3419 from halkyon/hhvm_tidy_fix

Fixing HHVM builds not having tidy support built-in to PHP (#3414)
Support PHPUnit 3.8+ compatibility

Summary:

PHPUnit 3.8+ adds a method to its PHPUnit_Framework_TestListener called addRiskyTest(). Need to stub it out to avoid "must implement this interface method" fatals when using 3.8+

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
Reformat .travis.yml
Merge pull request #3423 from tractorcow/pulls/3.1/travis

Reformat .travis.yml
BUG Fixing Director::test() failing on BASE_URL prefixed URLs

Example: you have a site in a sub-directory off the webroot, you call
->Link() on a SiteTree record, which returns "/[sitedir]/my-page", and
you pass this URL to Director::test(). It's a valid URL, but
Director::test() will throw a 404.

Director::test() should be ensuring that all URLs passed to it are
properly made relative, not just in the case where it thinks the URL
is absolute.
Merge pull request #3424 from halkyon/director_test_relative

BUG Fixing Director::test() failing on BASE_URL prefixed URLs
FIX Opt-out pf form message escaping (fixes #2796)

This fixes a limitation introduced through http://www.silverstripe.org/ss-2013-008-xss-in-numericfield-validation/.
Form messages used to accept HTML, now they’re escaped by default, effectively removing the ability
to pass in HTML and take care of escaping manually.

We pass through HTML to message in core through the CTF system, so this needs to be fixed.
It’s an alternative fix to https://github.com/silverstripe/silverstripe-framework/pull/2803.
Merge pull request #3418 from halkyon/remove_supression

Remove @ suppression operator on session_start()
Merge pull request #3406 from ss23/patch-2

Update urlvariabletools.md