doxygen: use inline jtag state maching image

The currently used image is 404 so use an inline image instead.

Change-Id: I56a0d187fd06dc2c5c370e6532d89815ccec63d6
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/1451
Tested-by: jenkins

Doxyfile.in

@@ -648,7 +648,7 @@ EXAMPLE_RECURSIVE      = NO
 # directories that contain image that are included in the documentation (see
 # the \image command).
 
-IMAGE_PATH             =
+IMAGE_PATH             = @srcdir@/doc/manual/images
 
 # The INPUT_FILTER tag can be used to specify a program that doxygen should
 # invoke to filter for each input file. Doxygen will invoke the filter program

doc/manual/primer/jtag.txt

@@ -14,8 +14,7 @@ just a logical interface that allows a uniform channel for communication.
 See @par
 	http://en.wikipedia.org/wiki/Joint_Test_Action_Group
 
-and @par
-	http://www.inaccessnetworks.com/projects/ianjtag/jtag-intro/jtag-state-machine-large.png
+@image html jtag-state-machine-large.png
 
 The first page (among other things) shows a logical representation
 describing how multiple devices are wired up using JTAG.  JTAG does not