add M3/H to/from L/H conversion

src/units.cc

@@ -34,7 +34,9 @@ using namespace std;
     X(MJ,  KWH,{vto=vfrom/1000.0/0.0036;}) \
     X(GJ,  MJ,  {vto=vfrom*1000.0;}) \
     X(M3,  L,  {vto=vfrom*1000.0;}) \
+    X(M3H, LH, {vto=vfrom*1000.0;}) \
     X(L,   M3, {vto=vfrom/1000.0;}) \
+    X(LH,  M3H,{vto=vfrom/1000.0;}) \
     X(C,   F,  {vto=(vfrom*9.0/5.0)+32.0;}) \
     X(F,   C,  {vto=(vfrom-32)*5.0/9.0;}) \
 

src/units.h

@@ -45,6 +45,7 @@
     X(L,l,"l",Volume,"litre")                 \
     X(KW,kw,"kW",Power,"kilo Watt")           \
     X(M3H,m3h,"m3/h",Flow,"cubic meters per hour") \
+    X(LH,lh,"l/h",Flow,"liters per hour") \
     X(C,c,"°C",Temperature,"celsius")         \
     X(F,f,"°F",Temperature,"fahrenheit")      \
     X(RH,rh,"RH",RelativeHumidity,"relative humidity")      \