Added Apache header to bm_sim module

Added Apache header to BMI module

Added Apache header to bf_lpm_trie module

Added Apache header to bm_runtime module

Added Apache header to Thrift IDL

Added Apache header to targets source files

Added Apache header to Python tool scripts

Added Apache header to all PD files

Added Apache header to target P4 files

Added Apache header to all C++ test files

Added Apache LICENSE file