Lots of bfarray refactoring
Lots of bfarray refactoring

Also, fix issue #76, performance issue with farray.__getitem__

cjdrake/pyeda,pombredanne/pyeda,karissa/pyeda,karissa/pyeda,karissa/pyeda,pombredanne/pyeda,GtTmy/pyeda,cjdrake/pyeda,sschnug/pyeda,sschnug/pyeda,GtTmy/pyeda,cjdrake/pyeda,pombredanne/pyeda,GtTmy/pyeda,sschnug/pyeda