Make Xcode debug info format controllable through a qmake variable

The default is still DWARF instead of DWARF with dSYM for static builds
of Qt, so that debug builds of the final application don't take forever
to build due to generating the dSYM file.

Change-Id: I370d800d7c959e05c1a8780c4ebf58fff250daa1
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
XCB: Print error code on Xlib I/O errors

When Xlib detects that its underlying XCB connection got into an error
state, it calls its I/O error handler. However, the default
implementation doesn't print the error code from XCB which might be
useful for debugging.

This commit adds an I/O error handler which prints the error code from
XCB with a string describing the error and then calls Xlib's default
error handler.

Change-Id: I7f1fb3f1e8d0fdc3ac9db03ae7d154330c31db0c
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Cocoa: Set the COCOA_MENU_ANCESTOR() also when sync'ing

Task-number: QTBUG-38044

Change-Id: I2769bf2f4beec058c15ba1d126e59106f41dab37
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Cocoa: Send expose event on screen change.

Required to repaint OpenGL content properly.

Task-number: QTBUG-38105
Change-Id: Ie9441d56bd9d1a4eb399210369592f03e19c4929
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>