Revert "Merge pull request #2390 from phptek/2389"

This reverts commit 58da57dd1b6b47d7e2e5a8ab109268bbae8e1c3b, reversing
changes made to 8864256601bb295f8a52ad2eea04c4e1f8087c1b.
NEW GDBackend can save interlaced image

Disabled by default use config GDBackend.image_interlace: 1 to enable
Default UploadField to replace files

Honours the $overwriteWarning setting, rather than warning
about overwritten files, and when that warning is acknowledged by the user,
create a new file instead. We need to set this as close to
the Upload->load() call as possible, since it depends
on non-deterministic config state.
i18nSSLegacyAdapterTest setting wrong arguments for manifest.

Currently if you run i18nSSLegacyAdapterTest twice in a row you
get errors about classes not existing, because the class manifest
doesn't get set correctly during the test setUp() method.
Revert "Style destructive actions destructively"

This reverts commit 3851ef9f2cc3a9a0301b5367e8788dd839af65b7.
Breaks button alignment in CMS.
Merge pull request #2598 from halkyon/test_execution_error

i18nSSLegacyAdapterTest setting wrong arguments for manifest.
Fixed support for single stage in Versioned

This used to work in 2.4, so is considered a regression.
To test, simply add a Versioned("Stage") extension to
some record in 2.4 vs. 3.1.
BUG Fix the password reset message to be shown consistently.

If we detect any of the password reset GET params, it's safe to assume
that someone intended a password reset, regardless of other conditions.
Merge pull request #2607 from mateusz/fix-reset-message

BUG Fix the password reset message to be shown consistently.
Merge pull request #2411 from simonwelsh/circ_ref

Revert "Merge pull request #2390 from phptek/2389"
Merge pull request #2604 from chillu/pulls/versioned-single-stage

Fixed support for single stage in Versioned
BUG Fix undefined index ID
Merge pull request #2621 from tractorcow/pulls/3.1-undefined-index

BUG Fix undefined index ID
Bad redirect in ChangePasswordForm->doChangePassword()
Merge pull request #2624 from JayDevlin/bad-redirect-in-changepasswordform

Bad redirect in ChangePasswordForm->doChangePassword()
Set default encoding for compass

See https://github.com/haml/haml/issues/269. Seems that OS X Mavericks causes this to occur, even when system default is set to utf-8.

Force encoding in admin scss as well
Merge pull request #2620 from kinglozzer/patch-2

Set default encoding for compass
Conditionally send "ID" val in UploadField

The "ID" form field is not always defined,
for example in the "Replace" tab of the "versionedfiles" module
(which uses GridFieldDetailForm). Since the path to that
detail form relies on the "ID" in AssetAdmin->currentPageID(),
and does an is_numeric() check to support the "root" folder,
we need to leave the "ID" param out completely.

Checked this without versionedfiles module in admin/assets
as well as a custom UploadField in CMSMain.
Merge pull request #2630 from chillu/pulls/uploadfield-id

Conditionally send "ID" val in UploadField
Merge pull request #2565 from colymba/progressive-images

NEW GDBackend can save interlaced images