Fixes #1739 - _.extend check for own properties
Merge pull request #1770 from jabbrass/extend-check-own-prop

Fixes #1739 - _.extend check for own properties
Fixes #1736 -- Underscore templates no longer accept a data argument -- just settings.
Merge branch 'master' of https://github.com/jashkenas/underscore
Test for inherited properties using a function constructor instead of Object.create
Merge pull request #1778 from akre54/inherited-props-test

Fix extend test for pre-es5 enviros
Fix invalid extend test: _.keys uses hasOwnProp
Merge pull request #1781 from akre54/inherited-props-test

Fix invalid extend test: _.keys uses hasOwnProp