Add libtool dependency in README.
Add libtool dependency in README.

Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice,patweb/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice-win32/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,kalev/libimobiledevice,libimobiledevice/libimobiledevice,patweb/libimobiledevice,libimobiledevice/libimobiledevice,kalev/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,kalev/libimobiledevice,upbit/libimobiledevice