Use xcrun to find SDK location, if available. Fix autoconf for newer env
Supply load.sh script for easy kext loading
Fixes 'zfs send' bug caused by premature fifo close.

Closing newstdout before the pthread_join would often corrupt
the send, by accidentally closing the fifo before the other
thread had finished with it.
Add .dirstamp to toplevel .gitignore
Remove two unnecessary Makefile.in files
Add simple kext load script
Merge remote-tracking branch 'origin/mavericks'

Conflicts:
	load.sh