xxHash r38

xxhsum can use stdin as input (default) - Suggested by Frank Reppin
Makefile : use OS default compiler

xxHash r37

• Updated API : please read xxhash.h before updating source file
• New utility named xxhsum

xxHash r36

• Provide null-length hash even on invalid input pointers
• XXHnn_init() checks memory allocation errors

xxHash r35

New : XXH64(), 64-bits hash version