Add 178663 back.

http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb went back green
before it processed the reverted 178663, so it could not have been the culprit.

Revert "Revert 178663."

This reverts commit 4f8a3eb2ce5d4ba422483439e20c8cbb4d953a41.
[analyzer] Fix typo.

Thanks Jordan!
[analyzer] Properly handle the ternary operator in trackNullOrUndefValue

1) Look for the node where the condition expression is live when checking if
it is constrained to true or false.

2) Fix a bug in ProgramState::isNull, which was masking the problem. When
the expression is not a symbol (,which is the case when it is Unknown) return
unconstrained value, instead of value constrained to “false”!
(Thankfully other callers of isNull have not been effected by the bug.)
[analyzer] make peelOffOuterExpr in BugReporterVisitors recursively peel off select Exprs
[analyzer] Warn when nil receiver results in forming null reference

This also allows us to ensure IDC/return null suppression gets triggered in such cases.
[analyzer] Rename “Mac OS X API”, “Mac OS API” -> “API Misuse (Apple)”

As they are relevant on both Mac and iOS.