The line with in the sc version is only 1px as a test.
Changed the icons to fit better into impress, modify insertfootnote ("i" slighty moved down).

Change-Id: I3d7813a016b78f5c6568686ae123009d58b9cc3c
Reviewed-on: https://gerrit.libreoffice.org/16261Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
(cherry picked from commit e60e55ce)