Shared Xcode schemes and C++11 changes

Hi Philipp,

Just a few minor changes here:

First, I added some shared Xcode schemes, which are used in automated builds of MWorks.

Second, I made a few tweaks to make the code compatible with C++11 builds of MWorks.  (The nightly is now built in C++11 mode, and the next release will be, too.)

Cheers,
Chris