more doc updates

darshan-runtime/doc/darshan-runtime.txt

@@ -485,10 +485,12 @@ mind when upgrading to Darshan 3.x:
 
 * Log file compatibility was broken in the upgrade, and thus 3.x log utilities do not
 work directly with logs generated by 2.x versions of Darshan (and vice versa).
-    - There is currently no tool for converting 2.x logs into the 3.x log format
+    - There is currently no tool for converting 2.x logs into the 3.x log format.
+    - The `darshan-logutils` library will provide error messages to indicate whether a given
+log file is incompatible with the correspnonding library version. 
 
 * The darshan log file extension has been changed from `.darshan.gz` (or `.darshan.bz2` for
-log files converted to use bzip2 compression) to `.darshan`
+log files converted to use bzip2 compression) to `.darshan`.
     - A field in the Darshan log header is used to indicate whether a log is compressed using
 libz or bzip2 compression.
 
@@ -496,7 +498,7 @@ libz or bzip2 compression.
 used for version 2.x.
     - Within this directory, the determination on which set of log utilities (version 2.x
 or version 3.x) to use can be based on the file extension for a given log (as explained
-above)
+above).
 
 == Runtime environment variables