OpenOCD now requires autoconf 2.60 to process AC_PROG_CC_C99 macro.

git-svn-id: svn://svn.berlios.de/openocd/trunk@1696 b42882b7-edfa-0310-969c-e2dbd0fdcd60

configure.in

-AC_PREREQ(2.59)
+AC_PREREQ(2.60)
 AC_INIT([openocd], [0.2.0-in-development],
 	[OpenOCD Mailing List <openocd-development@lists.berlios.de>])
 AC_CONFIG_SRCDIR([src/openocd.c])