Nanometric work. Design rules, D_PAD (except m_Pos) is now in new units. Metric files can be loaded w/o KICAD_NANOMETRE flag set but saved only with this flag, this could help to gain some compatibility during transition process. ifdef'd code is somewhat minimized by using transition macros. Some potential code bugs are commented.

common/common.cpp

@@ -416,7 +416,7 @@ int ReturnValueFromString( EDA_UNITS_T aUnit, const wxString& TextValue, int Int
  *New common length functions
  */
 
-const LENGTH_UNIT_DESC g_MillimetreDesc =
+const LENGTH_UNIT_DESC MillimetreDesc =
 {
     LENGTH_UNITS<LENGTH_DEF>::millimetre(),
     wxT( "mm" ),
@@ -424,7 +424,7 @@ const LENGTH_UNIT_DESC g_MillimetreDesc =
 };
 
 
-const LENGTH_UNIT_DESC g_InchDesc =
+const LENGTH_UNIT_DESC InchDesc =
 {
     LENGTH_UNITS<LENGTH_DEF>::inch(),
     wxT( "\"" ),
@@ -432,7 +432,7 @@ const LENGTH_UNIT_DESC g_InchDesc =
 };
 
 
-const LENGTH_UNIT_DESC g_MilDesc =
+const LENGTH_UNIT_DESC MilDesc =
 {
     LENGTH_UNITS<LENGTH_DEF>::mil(),
     wxT( "mil" ),
@@ -440,7 +440,7 @@ const LENGTH_UNIT_DESC g_MilDesc =
 };
 
 
-const LENGTH_UNIT_DESC g_UnscaledDesc = /* stub */
+const LENGTH_UNIT_DESC UnscaledDesc = /* stub */
 {
     LENGTH_DEF::quantum(),
     wxT( "" ),
@@ -451,11 +451,11 @@ const LENGTH_UNIT_DESC g_UnscaledDesc = /* stub */
 const LENGTH_UNIT_DESC *UnitDescription( EDA_UNITS_T aUnit ) {
     switch(aUnit) {
         case INCHES:
-            return &g_InchDesc;
+            return &InchDesc;
         case MILLIMETRES:
-            return &g_MillimetreDesc;
+            return &MillimetreDesc;
         default:
-            return &g_UnscaledDesc; /* should not be reached */
+            return &UnscaledDesc; /* should not be reached */
     }
 }
 
@@ -533,15 +533,15 @@ LENGTH_DEF StringToLength( const LENGTH_UNIT_DESC *aUnit, const wxString& TextVa
 
     if( unit == wxT( "in" ) || unit == wxT( "\"" ) )
     {
-        aUnit = &g_InchDesc;
+        aUnit = &InchDesc;
     }
     else if( unit == wxT( "mm" ) )
     {
-        aUnit = &g_MillimetreDesc;
+        aUnit = &MillimetreDesc;
     }
     else if( unit == wxT( "mi" ) || unit == wxT( "th" ) ) /* Mils or thous */
     {
-        aUnit = &g_MilDesc;
+        aUnit = &MilDesc;
     }
 
     Value = LENGTH_DEF( dtmp * LENGTH< double, 1 >( aUnit->m_Value ) );