Pcbnew: enhancements:

Plot Gerber format default values:  X2 attributes enabled.
Gerber job file: use a trick to truncate floating values to 4 digits in mantissa.
It gives a much better readability and 0.1 micron is enough for
mechanical dimensions

pcbnew/pcb_plot_params.cpp

@@ -97,9 +97,9 @@ static bool setDouble( double* aTarget, double aValue, double aMin, double aMax
 PCB_PLOT_PARAMS::PCB_PLOT_PARAMS()
 {
     m_useGerberProtelExtensions  = false;
-    m_useGerberX2format          = false;
-    m_includeGerberNetlistInfo   = false;
-    m_createGerberJobFile        = false;
+    m_useGerberX2format          = true;
+    m_includeGerberNetlistInfo   = true;
+    m_createGerberJobFile        = true;
     m_gerberPrecision            = gbrDefaultPrecision;
     m_excludeEdgeLayer           = true;
     m_lineWidth                  = g_DrawDefaultLineThickness;