for the creation and modification of targets.

In file gmp.c:
  Extended the structs create_target_data_t and
  modify_target_data_t and the enum client_state_t. Adjusted the
  functions gmp_xml_handle_start_element and
  gmp_xml_handle_end_element. Adjusted the function call of
  modify_target and create_target in gmp_xml_handle_end_element.

In file manage_sql.c:
  Extended the functions create_target and modify_target with the
  new field ssh_elevate_credential and added the required
  functionality.

(cherry picked from commit 049b4de)

Added documentation of the parameter ssh_elevate_credential at the
call of create_target.
Added documentation of the parameter ssh_elevate_credential_id at
the call of modify_target.

(cherry picked from commit a40fa21)

in file gmp.c:
  Added the necessary data structures and code to get the new
  credential to the function handle_get_targets().

in manage_sql.c:
  Extended the TARGET_ITERATOR_COLUMNS and
  TARGET_ITERATOR_FILTER_COLUMNS for the new credential.
  Added the functions target_iterator_ssh_elevate_credential(),
  target_iterator_ssh_elevate_trash() and
  target_ssh_elevate_credential().

(cherry picked from commit 133eecd)

…tial

(cherry picked from commit 605b24c)

# Conflicts:
#	CHANGELOG.md

(cherry picked from commit 999d56f)

(cherry picked from commit e7281cf)

(cherry picked from commit 4b4862d)

(cherry picked from commit db13a38)

(cherry picked from commit 3df5829)

in manage_sql.c:
  Added a check, if there is a ssh_credential when a
  ssh_elevate_credential is given, in the functions
  create_target() und modify_target(). If there is
  no ssh_credential an error code is returned.

in gmp.c:
  Added the according error messages to the error messages
  sections behind the call of create_target() and
  modify_target().

(cherry picked from commit 371ed32)

in manage_sql.c:
  Adjusted and added the documentation of the return
  values concerned by the new SSH Elevate Credential in
  the Doxygen-comments of the functions create_target()
  and modify_target().

(cherry picked from commit dca05f3)