Merge commit for internal changes

Fixed conflicts:
	tensorflow/core/BUILD
	tensorflow/core/kernels/fixed_length_record_reader_op.cc
	tensorflow/core/ops/ops.pbtxt
	tensorflow/docs_src/programmers_guide/version_semantics.md
	tensorflow/python/kernel_tests/cwise_ops_test.py
	tensorflow/tools/dist_test/python/mnist_replica.py
	third_party/lmdb.BUILD
	third_party/snappy.BUILD
	third_party/zlib.BUILD