add to ColumnManipulation methods

[sagivba]

• split_to_columns(column,split_func,splited_columns_name) : returns tuple of colomns

• drop_columns(df,columns_list) returns df without the columns_list

• apply_by_dict(df, **kward)
  for key, value in kwargs.iteritems():
  if key not in list(df):
  print warn not in columns list
  continue
  if value is function:
  value=[value]
  if value int iterable:
  print warn
  for f in value
  df[key]=df[key].apply(f)
  return df