* Replace long GC_markers global variable with int GC_markers_m1.
* Replace pointer relational comparisons with non-pointer ones.
* Replace printf PRIxMAX specifier with '%p' for thread id debug output.
-* Require automake 2.63 instead of v2.64.
+* Require automake 2.61 instead of v2.64.
* Simplify autogen.sh (use autoreconf).
* Split GC_abort with GC_on_abort and abort() invoked from ABORT.
* Support GC_ATTR_MALLOC for MS VisualStudio.