add framer-tdma.c module for tdma MAC header
verify BS hdr
fix #10.
Merge pull request #24 from s3lsensor/yzliao_v0.2_mac_hdr

Add Mac Header pull request #18 (re-merge)
Issues # 19,20,13(partial). Support for 100s of slots per sec
Issues # 19,20,13(partial). Support for 100s of slots per sec