Safeguard against passing NULL pointer to xpc_release() and dispatch_release()

Both functions would crash on NULL parameters
Merge branch 'master' of github.com:iMediaSandboxing/XPCKit
Updated to recommended project settings.
Do not only build for active architecture

Active architecture is set to i386 for some strange reason on a RMBP
Do not only build for active architecture

Active architecture is set to i386 for some strange reason on a RMBP
Merge branch 'master' of github.com:iMediaSandboxing/XPCKit
Add explicit reply dispatch queue to XPCConnection so that it is not primarily dependent on dispatch_get_current_queue() (This is a partial solution to issue #1)
Merge remote-tracking branch 'upstream/master'

Conflicts:
	XPCKit.xcodeproj/project.pbxproj