New : LZ4 HC streaming mode
Fixed : LZ4F_compressBound() using null preferencesPtr
Updated : xxHash to r38
Updated library number, to 1.4.0

git-svn-id: http://lz4.googlecode.com/svn/trunk@124 650e7d94-2a16-8b24-b05c-7c0b3f6821cd