Changed _element_constructor_ on Braid groups
Added an_element, some_elements and a TestSuite doctest to braid groups
Corrected typo
Trac #16458: Braid group creates elements in wrong class

Right now we have this inconsistency.

{{{
sage: B=BraidGroup(4)
sage: b=B([1,2,3])
sage: type(b)
<class 'sage.groups.braid.Braid'>
sage: type(b*b)
<class 'sage.groups.braid.BraidGroup_class_with_category.element_class'>
}}}

Both should be in the same class.

URL: http://trac.sagemath.org/16458
Reported by: mmarco
Ticket author(s): Miguel Marco
Reviewer(s): Vincent Delecroix