Update -rac_returnValue: to support arbitrary types.
Remove reference to type limitations.
Added back char pointer lifting tests.
Add back string support to RACTypeParsing.
Updated change log.
Added Assertion for 0-Tuple for -and, -or
Merge pull request #690 from ReactiveCocoa/update-documentation

Update documentation for 2.0 deprecations
Improved language in header comments for -and/-or
Assert wording consistency for -and/-or
Pluralisation for -and/-or asserts
Boxing is implied, all signals return objects
Refactor -invalidateGlobalRefIfNoNewSubscribersShowUp

Specifically, avoid block allocations (by avoiding variable capture), and only check RACActiveSignals once per run loop iteration.
Don't allocate RACSignal->_subscribers until needed
Avoid -tupleByAddingObject: in zip/combine

This reduces the number of allocations performed as the number of streams grows.
Revert "Updated change log."

This reverts commit 50052771057c3dd8617b7caf0831b2a4a2e562ea.
Removed section about char * lifting from change log.
Add vertical whitespace.
Switch the dynamically allocated buffers with local variables.
Add back test for lifting const char *.
Add test for structs.