Add 'bk license -v' command to validate licenses and to extract them  from emails.
Add 'bk license -v' command to validate licenses and to extract them 
from emails.

bk: 3d99ba2bzisGmX2d8Tlv0WEoqb-frg
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper