iOS: Switch to using UIApplicationMain() in dw_main(). This is not a long term solution since it never exits and has some other limitations, but apparently it does some setup we were not doing. We are now getting auto constraint errors due to conflicts with the DW layout engine. Some changes to avoid these but still getting them... so more work needed.

# Set these here to change the version for all platforms
DW_MAJOR_VERSION=3
DW_MINOR_VERSION=2