Add BARCODE_MEMORY_FILE to symbol->output_options to allow

outputting to in-memory buffer `symbol->memfile` instead of to
  file `symbol->outfile`, ticket #301
Add "README.clang-tidy" and ".clang-tidy" options file
Suppress some warnings

backend_tcl/configure

@@ -5361,6 +5361,7 @@ printf "%s\n" "$ac_cv_c_bigendian" >&6; }
 	../backend/dotcode.c
 	../backend/eci.c
 	../backend/emf.c
+	../backend/filemem.c
 	../backend/general_field.c
 	../backend/gif.c
 	../backend/gridmtx.c

backend_tcl/configure.ac

@@ -90,6 +90,7 @@ TEA_ADD_SOURCES([
 	../backend/dotcode.c
 	../backend/eci.c
 	../backend/emf.c
+	../backend/filemem.c
 	../backend/general_field.c
 	../backend/gif.c
 	../backend/gridmtx.c

backend_tcl/zint_tcl.dsp

@@ -161,6 +161,10 @@ SOURCE=..\backend\emf.c
 # End Source File
 # Begin Source File
 
+SOURCE=..\backend\filemem.c
+# End Source File
+# Begin Source File
+
 SOURCE=..\backend\general_field.c
 # End Source File
 # Begin Source File