update changelog for 3.0.1 release

ChangeLog

@@ -2,6 +2,27 @@
 Darshan Release Change Log
 --------------------------
 
+Darshan-3.0.1
+=============
+* bug fix in darshan logutil mount parsing code that was
+  causing file paths to be matched to the first mount point
+  with a common prefix rather than the one with the longest
+  common prefix
+* bug fix in the darshan-util bzip2 configure check that
+  was accidentally overwriting Darshan's LDFLAGS
+* minor bug fixes to IO start time counters in all modules
+  to set IO start time to the actual first start time rather
+  than the first IO op to complete
+* update darshan-util perl scripts to get perl bin from
+  user's path, rather than from /usr/lib (reported by
+  Kay Thust)
+* update Darshan's fortran and cxx compiler wrapper generators
+  to automatically detect MPICH library names on BG/Q
+* fix bug that was calculating Darshan's agg_perf_by_slowest
+  performance metric incorrectly
+* add performance estimate info to darshan-job-summary
+  graphs
+
 Darshan-3.0.0
 =============
 * install darshan-null-log-format.h header when installing