Doxygen: enable source code browser

Doxyfile.in

@@ -984,7 +984,7 @@ USE_MDFILE_AS_MAINPAGE =
 # also VERBATIM_HEADERS is set to NO.
 # The default value is: NO.
 
-SOURCE_BROWSER         = NO
+SOURCE_BROWSER         = YES
 
 # Setting the INLINE_SOURCES tag to YES will include the body of functions,
 # classes and enums directly into the documentation.
@@ -997,13 +997,13 @@ INLINE_SOURCES         = NO
 # Fortran comments will always remain visible.
 # The default value is: YES.
 
-STRIP_CODE_COMMENTS    = YES
+STRIP_CODE_COMMENTS    = NO
 
 # If the REFERENCED_BY_RELATION tag is set to YES then for each documented
 # entity all documented functions referencing it will be listed.
 # The default value is: NO.
 
-REFERENCED_BY_RELATION = NO
+REFERENCED_BY_RELATION = YES
 
 # If the REFERENCES_RELATION tag is set to YES then for each documented function
 # all documented entities called/used by that function will be listed.