OS X: Do not default to non-existent deployment target SDK

Since commit 95f78e08 (OS X: Search for SDK based on deployment target,
2013-08-02) we select the default OS X SDK path to match the deployment
target.  Fix this behavior in the case that the matching SDK does not
exist and fall back to the SDK for the current host OS X version.
CMake Nightly Date Stamp
Do not warn about left paren not separated by a space

Since commit 58e52416 (Warn about arguments not separated by whitespace,
2013-02-16) we warn about arguments not separated by spaces.  Loosen the
warning to not complain about left parens not separated by spaces from
the preceding token.  This is common in code like "if(NOT(X))".

Teach the RunCMake.Syntax test to cover cases of left parens not
separated by spaces and check that no warning appears.
Merge topic 'osx-sysroot-default'

335a127 OS X: Do not default to non-existent deployment target SDK
Merge topic 'cmake-syntax'

9040ec9 Do not warn about left paren not separated by a space