Switch to side-by-side view

--- a/src/sampleconf/mimemap
+++ b/src/sampleconf/mimemap
@@ -17,6 +17,7 @@
 .c   = text/x-c
 .cc  = text/x-c
 .cxx = text/x-c
+.hxx = text/x-c
 .f   = text/x-fortran
 .py  = text/x-python
 .awk = application/x-awk