Log Message:
Update to newest version 9.18.
While there, make it compatible with perl 5.18.

Changes:

9.18 Sun Mar 24 15:33:35 CET 2013
	- fix regression that caused artifacts on resize.

9.17 Fri Mar  1 13:46:08 CET 2013
	- add shade operator in background perl extension.
        - avoid starting or ending the selection in the middle of wide
          characters to avoid artifacts (reproted by Tiago Resende).
	- fix artifacts that may occur if the character in the cursor
	  cell has width > 1 (reported by Tiago Resende).
	- fix regression that causes artifacts on scrolling if
	  saveLines is 0 and the window is resized (reported by Bert
	  Münnich).
	- fix build when perl is enabled and pixbuf and transparency
	  are disabled.