Relaxing composer dependencies

You currently can't install 3.1.0-beta1 through modifying your composer.json, because dependency checks will fail.
Removed direct sprintf() usage from _t() calls

Parameterized strings are easier to understand,
and more fail-proof, don't fatal out when not enough sprintf() args
Merge remote-tracking branch 'origin/3.0' into 3.1
BUG SiteTree_Information.ss was not making use if i18n translations
Merge pull request #266 from silverstripe-rebelalliance/8151

BUG SiteTree_Information.ss was not making use if i18n translations
BUGFIX Disable CMS preview for RedirectorPage (fixes #7127)

If the redirect is to an internal page, the preview iframe
will automatically load this new URL, causing the CMS edit
form to switch as well - effectively making it impossible
to edit a redirector page in the CMS as soon as it is saved
with an internal redirection target.
BUG: dependentPages grid field not showing necessary columns and their values.
ENHANCEMENT Writing caching metadata as HTML comments in FilesystemPublisher (through StaticPublisher::$include_caching_metadata) (ischommer)
NEW SiteTree->PreviewLink() for fine grained URL control
Don't duplicate SS_Report title in GridField
Moving "edit tree" button next to "add new" (fixes #8119)
Fixed "add page" type icons (fixes #8190)
MINOR: Grammar error
Merge pull request #274 from unclecheese/patch-2

MINOR: Grammar error
BUG Only use $.button in onunmatch if init'ed (fixes #8181)
Merge remote-tracking branch 'origin/3.0' into 3.1
More useful default cols on "Pages" list (fixes #8199)
BUG: Replaced extendedSQL with DataList as per ticket 8183
Merge pull request #277 from silverstripe-rebelalliance/open/8183

BUG: Replaced extendedSQL with DataList as per ticket 8183