There's a clang bug [2] where if a selector is marked as unavailable,
it's marked as unavailable for every class, not just the class where
the unavailable selector is.
This means that we can't do `[super initWithCoder:x]` anywhere,
because `initWithCoder:` is marked as unavailable for UIActivityViewController.
So instead rewrite the call to super to call objc_msgSendSuper
directly, circumventing clang's broken availability checks.
[1] https://bugzilla.xamarin.com/show_bug.cgi?id=41319
[2] https://llvm.org/bugs/show_bug.cgi?id=28058
mtouch only uses Xamarin.Mac to read plists, so change to use
our purely managed plist reader in Xamarin.MacDev instead.
That makes us able to change mtouch to be a normal command-line
executable (and project).
Which makes it logical to not mkbundle mtouch anymore,
it executes just fine with the system mono (and there's
no code to protect anymore either).
And since mmp and mtouch share some files, do the same
for mmp.