Add third flag to throttle resembling debounce

[Addresses #926]
Merge pull request #1019 from brysgo/master

Add `immediate` flag to `throttle()`
Using push to unify the way to adding to array. fix Issue #1025
Merge pull request #1027 from stonelee/issue1025

Using push to unify the way to adding to array. fix Issue #1025
adds test using multiplication to reduce
Merge pull request #1028 from logicmason/master

adds a test using multiplication to reduce
Add Underscore's license to package.json
Merge pull request #1035 from theoreticaLee/master

Add underscore license to package.json
Merge pull request #1038 from almost/master

_.unzip as the inverse of _.zip
Added return value info to _.times docs.
Phantomjs 1.9.0-1.
Re-write _.times in terms of _.map and _.range
Less pretty but much faster
Merge pull request #1048 from almost/times-negative

_.times should treat negative numbers as 0 instead of throwing an error
whitespace
Merge pull request #1045 from rsml/rsml/times-docs

Added return value info to _.times docs.
Merge branch 'master' of https://github.com/documentcloud/underscore into unzip-no-sparse
Make use of _.times new found ability to deal with negatives