Replaced 'core' with 'main'.
Other minor updates.
diff --git a/doxygen/common.doxy b/doxygen/common.doxy
index 284cdc6..022085e 100644
--- a/doxygen/common.doxy
+++ b/doxygen/common.doxy
@@ -23,7 +23,7 @@
 # This could be handy for archiving the generated documentation or 
 # if some version control system is used.
 
-PROJECT_NUMBER         = 5.1
+PROJECT_NUMBER         = 6.1
 
 # The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute) 
 # base path where the generated documentation will be put.