changed to hasMethod
Merge branch 'GridFieldFix' of git://github.com/dnadesign/silverstripe-framework into 3.1

* 'GridFieldFix' of git://github.com/dnadesign/silverstripe-framework:
  changed to hasMethod
Merge branch '3.1' of git://github.com/dnadesign/silverstripe-framework into 3.1

# By Damian Mooyman (4) and others
# Via Damian Mooyman (8) and others
* '3.1' of git://github.com/dnadesign/silverstripe-framework: (21 commits)
  Remove PHP 5.6 from allowed failures
  FIX Add support for compositedbfield within many_many_extraFields
  Update i18n.php
  Adding some more commonly used SS_Log priority constants.
  Update javascript.md
  Better support for overloading start and destroy methods in Session
  Fixes to the :::ss parsing - extra tabs were breaking it.
  Update forms.md with additional code in MyForm.ss
  FIX: ClassManifest errors if files contain duplicate class names (fixes #3210)
  Moved table-related feature steps to behat extension
  Fetch the nearest Controller instead of relying on global state.
  BUG fix dependency injection stumbling over ViewableData's __isset
  Versioned no longer sets redundant session data
  BUG Sanitise the PHP output.
  Update Form.php
  DOCS Explicitly exclude dev deps for deployment
  Update modeladmin.md
  Update for Mink 1.6 compatibility
  added in a getter
  BUG Fix grid field showing search without search component added ref: CWPBUG-133
  ...