Updated _.isFinite to match ES5 and ES6 spec

The EcmaScript 5 and 6 spec define isFinite as returning false only if
ToNumber(number) is NaN, Infinity, or −Infinity.

Current implementation of _.isFinite acts as if ToNumber('42') is NaN.
This commit fixes it while also catching the special gotcha in the spec
where isFinite(' ') returns true.

It's also much faster than current implementation.
Merge pull request #830 from TalAter/isfinite

Updated _.isFinite to match ES5 and ES6 spec
Fix #834 - Provide documentation for _.unescape.
Specify unescaped entities.
Merge pull request #835 from braddunbar/unescape-docs

Fix #834 - Provide documentation for _.unescape.
Native-like names in documentation for _.all and _.any methods
Merge pull request #836 from Shutnik/master

Native-like names in documentation for _.all and _.any methods
Juggle arguments in `_.uniq` to allow an argument signature of `array, iterator, context`

Issue 832: Juggle arguments in `_.uniq` to allow an argument signature
of `array, iterator, context`
Remove local variable from `contains`
Merge pull request #850 from kjbekkelund/simplify-contains

Remove local variable from `contains`
Merge pull request #849 from mikez302/uniq-arguments

Fix #832 - Juggle arguments in `_.uniq` to allow an argument signature of `array, iterator, context`.
Fixes #856 -- use local var for arguments length check.
Merge branch 'master' of github.com:documentcloud/underscore
Fixes #854 -- return values for non-numeric comparisons.
Fixes #647 -- removes old closure compiler pessimization.
Fixes #838 -- use hasOwnProperty when looping through _.where attrs, for healthy paranoia's sake
Fixes #864 -- add a default iterator to groupBy and countBy
toArray: only call Array.prototype.slice on actual arrays.

Specifically, this fixes _.toArray on NodeList objects on IE8, which worked in
Underscore 1.3.3 but throws "JScript object expected"  in 1.4.0.
Updated an old link to Prototype.js' API docs.
Merge pull request #870 from Ore4444/patch-1

Updated an old link to Prototype.js' API docs.