This lists only the changes for the current release (v1.16) over the last
version, since HISTORY is now quite big:

* Math::String::Charset:
  + split Charset.pm into
	Math::String::Charset::Simple		(type = 0, order = 1)
	Math::String::Charset::Nested		(type = 0, order > 1)
	Math::String::Charset::Grouped		(type = 1, order = 1)
  + support for minlen and maxlen
  + added ones(), count(), zero(), one() and tests for these
  + next/prev actually work
  + analyze is alias for study, can export analyze
  + better error handling upon initialization
  + added type()
  + is now subclassable
  + first()/last() work now with sep char, added tests for that
  + make Math::String->first($length,$set) work	(and last(), too), test for it
  + study: 
      - 'chars' and 'start' for depth => 1
      - depth as alias for order
      - can return histogram (hist => 1)
      - now works for the "hocuspocus" example
      - tests are now in seperate file

* Math::String::Charset::Nested
  + bi-gram chars that have no followers can't be in _start (but can be in
    the _ones set), tests for that
  + first(), last() work now as expected
  + class() was wrong if not all chars in set were also in the start set
  + can have empty ones set (minlen == 2 in this case)
  + check for minlen > 2 (class(2) == 0)

* Math::String:
  + binc(), bdec() modify (instead clear) the cache to avoid costly recalcs
  + added bone(), is_valid(), minlen(), maxlen(), type(), class()

