darwin: clean up some code. remove a clang warning

The check for NULL != cached_device was unnecessary and caused clang's
static analysis to print out a warning.
darwin: return libusb error codes instead of kernel error codes and fix
a bug introduced in the last commit.
Merge remote-tracking branch 'upstream/master'
Release 1.0.17-rc1

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Android: Add android build files to source tarball

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Makefile.am: Add Xcode dir to EXTRA_DIST

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Remove unused THANKS file

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Nathan is a maintainer now, so add him to the README

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Windows: Address an VS2012/x64 warning in hotplug.c

..\libusb\hotplug.c(255): warning C4244: '=' : conversion from
'ssize_t' to 'int', possible loss of data
Merge remote-tracking branch 'upstream/master'