Removed RACActiveSignals checking in RACDynamicSignal.
Fixed some tests.
Removed some tests that were testing implementation details.
Isolated multicasted subscription disposal test because ARC.
This isn't needed anymore.
Return nil if count is 0.

This fixes an issue where `RACIndexSetSequence`
would return data from `self.indexes` in `head`
even if it represented an empty index set.
It now returns `nil` if it represents an empty
set.
Fix typo in README
Copy Mac .a headers into include/ReactiveCocoa.

Previously they were copied into include/ReactiveCocoa-Mac, which meant
that they couldn’t be found by the usual #import <ReactiveCocoa/…>
directive.
Copied Mac .a headers include umbrella & EXT*.

They’re required for projects linking against libReactiveCocoa.a which
desire to use the umbrella header and these other headers.
Merge pull request #1205 from camdez/master

Fix typo in README
Fix bug in NSIndexSet tests.

The test for NSIndexSet+RACSupport includes a
block that returns an array of all values in an
index set. This block mistakenly referenced a
captured index set declared outside of itself
instead of referring to its sole parameter.
Add a test for empty index sets.
Merge pull request #1204 from ReactiveCocoa/mac-static-lib-includes

Mac static lib includes
Better solution to the empty index set problem.

Return `[self empty]` early if the index set
contains no indexes.
Code style.
Merge pull request #1203 from calebd/bug-fix-nsindexset

Return nil if count is 0 in RACIndexSetSequence
fixed a missing semicolon in the Readme
Merge pull request #1222 from 343max/syntaxFixes

fixed a missing semicolon in the Readme
Add RACTuple.tail
Add RACSignal.ap