Updated constructor to accept tags, added filter and match methods, and added namespace support. Missing some unit tests.

Signed-off-by: Stephen Young <young.steveo@gmail.com>
Fixing broken unit tests
Fixed some namespacing issues.  Ynit tests passing.
Added some new unit tests for Bitmask::filter and Bitmask::match, and adjusted Bitmask::add in the process to accept a mask value.
Updated the filtering to use custom private methods.  Updated unit tests.
Updating the readme and bumping the version