Update pick and omit to accept a predicate
Merge branch 'pick-pred' of https://github.com/jasonLaster/underscore into pick-omit
Update pick/omit to take a function callback.

* Clean up tests.
* Branch for iterator case.
Update documentation.
Revert call signature change.
Spacing.
Loops.
Merge pull request #1485 from braddunbar/pick-omit

_.pick and _.omit accept a predicate
_.omit via _.pick
Merge pull request #1501 from mehdishojaei/improve-omit

_.omit via _.pick
clean implementation of _.omit; it can be even cleaner if we add _.not
add _.complement
define _.reject as the complement of _.filter
Merge branch 'complement' of https://github.com/davidchambers/underscore
Fixes #1503. Stops the bikeshedding.
use _.negate in definition of _.omit; see 112e082c0f9e859d36ee1252f602b3a87774c34a
fixes #1505: _.omit can't take non-string property names