added bulk option to lower the overhead for tagging data stream.
bulk option is added at expense of number of available tag.
available value of tag will be 0-62 if it bulk is enabled, the first 2 bit of tag byte is used to indicate number of consecutive data bytes followed.
by default, 00=>1byte 01=>4bytes 10=>16 bytes 11=>64 bytes.
this mapping can be configured by user by --bulk=A,B,C option
the number of maximum consecutive data byte is limited to 64 because that is the maximum number of bytes sent to InMethod of tag filter observed during some testing. Moreover, increase the bulk step number further will not decrease the percentage overhead much.