Updated runtime files.
updated for version 7.4.553
Problem:    Various small issues.
Solution:   Fix those issues.
Added tag v7-4-553 for changeset e13f8073c9f9
updated for version 7.4.554
Problem:    Missing part of patch 7.4.519.
Solution:   Copy back regprog after calling vim_regexec.
Added tag v7-4-554 for changeset 7e4c22ecc679
updated for version 7.4.555
Problem:    test_close_count may fail for some combination of features.
Solution:   Require normal features.
Added tag v7-4-555 for changeset c12439378869
updated for version 7.4.556
Problem:    Failed commands in Python interface not handled correctly.
Solution:   Restore window and buffer on failure.
Added tag v7-4-556 for changeset a35752526cd0
updated for version 7.4.557
Problem:    One more small issue.
Solution:   Update function proto.
Added tag v7-4-557 for changeset fcd5a3207100