Minor _.result optimization :)

Don't hate me

Mentioned this in #1515 a couple weeks ago
Merge pull request #1578 from megawac/result-optimization

Most minor _.result optimization :)
fixes #1575: underscorejs.org toc items way too wide
Remove changing nativeSome in tests

A side effect of this is that IE<=8 will pass tests more regularly
Merge pull request #1581 from megawac/patch-1

Remove nullifying Array.prototype.some in tests
Add a message to TypeError from _.bind
Merge pull request #1589 from mattrobenolt/patch-1

Add a message to TypeError from _.bind
Simply assert that a TypeError is raised
Merge pull request #1591 from mattrobenolt/better-test

Simply assert that a TypeError is raised
Abstract iterator binding to createIterator

Long coming optimization discussed in 1525, 1561 and elsewhere.
Follows lodash's lead.
Closes #1561; add lookupIterators as appropriate

See included tests and lodash docs for some examples

LookupIterators maps string properties (see #1557) and objects to
_.matches.

As a result several of the helper functions such as _.where, _.pluck,
_.findWhere are handled by their parent implementations.
Edge case compat for findWhere, where, pluck

As discussed in PR with jdalton and @bradunbar