<Purpose>
    Gets the list of all valid tab-complete strings from all enabled modules.
  <Arguments>
    input_list: The list of words the user entered.
  <Side Effects>
    None
  <Exceptions>
    None
  <Returns>
    A list of valid tab-complete strings

def tab_complete(input_list):
  """
  <Purpose>
    Gets the list of all valid tab-complete strings from all enabled modules.
  <Arguments>
    input_list: The list of words the user entered.
  <Side Effects>
    None
  <Exceptions>
    None
  <Returns>
    A list of valid tab-complete strings
  """
  commands = []
  for module in get_enabled_modules():
    if 'tab_completer' in module_data[module]:
      commands += module_data[module]['tab_completer'](input_list)
  return commands