ENH: pytables start/stop/selection fixes and select_as_mutlipe change

This commit fixes issues with start/stop and selection. Furthermore
select_as_mutlipe is implemented differently:
- select_column and remove now hanlde start/stop arguments
- select_as_multipe hanldes start/stop the same way as select
- select_as_coordinates and select_column works with where expressions
  that result in filters. This also fixes select_as_multipe with filters
- select_as_multipe table iterator is rewritting, so memory usage is
  constant.

select_as_multiple now will always throw a KeyError if either a key or
the selector is not found.