BUG Text::BigSummary() fails with undefined $data when $plain = false
BUG File attach handler is no longer accessible if attachment is disallowed or disabled
Merge pull request #3576 from tractorcow/pulls/3.1/upload-attach

BUG File attach handler is no longer accessible if attachment is disallowed or disabled
Merge pull request #3521 from halkyon/bigsummary_plain_fix

BUG Text::BigSummary() fails with undefined $data when $plain = false
Moving NoHTML function from Text to StringField

This change will make the NoHTML function available for Varchar fields in particular.
FIX GridFieldExportButton exporting only Paginated list when using ArrayList as source
Improvements to nginx and HHVM installation docs

 * Fix a few missing packages in `apt-get install` command
 * Add command to start HHVM automatically on boot
 * Remove unnecessary `sendfile on` (already in /etc/nginx/nginx.conf)
belongs_many_many are now translatable
Merge pull request #3582 from g4b0/3581-translate_belongs_many_many

belongs_many_many are now translatable
Merge pull request #3580 from halkyon/hhvm_install_docs_cleanup

Improvements to nginx and HHVM installation docs
Merge pull request #3567 from stephenmcm/gridfieldexportbutton-patch

FIX GridFieldExportButton exporting only Paginated list when using ArrayList as source
FIX: Image resizing breaks when one of the resized image dimensions is between 0 and 1.
Solution: Round up to 1 instead of down to 0.
Converted php errors to exceptions in the process.
Correct regression around ?flush

?flush used to work. There's no reason why it shouldn't.
Merge pull request #3593 from simonwelsh/patch-1

Correct regression around ?flush
Merge pull request #3591 from jedateach/issues/image-resize-fix

FIX: Image resizing breaks when one of the resized image dimensions is between 0 and 1
Update Requirements.php

Makes requirements inclusion work with old PCRE versions
Merge pull request #3594 from jdemeschew/patch-1

Makes requirements inclusion work with old PCRE versions.
Bugfix NumericField shows (none) for 0 on readonly
Merge pull request #3553 from nhorstmeier/NumericReadonlyField

Bugfix NumericField shows (none) for 0 on readonly
Merge remote-tracking branch 'upstream/3.1' into 3.1