[PcbDraw] Various changes in resistor color bands

- Added support for values between 0.01 and 10 ohms
- Avoid crash for R<0.01 ohms
- Added support for 20% tolerance
- Added support for tol/tolerance property
- Fixed Decimal division by float
- Changed default tolerance to 20%. I know this isn't reality,
  but if we don't know the tolerance is better to just let it
  blank (20% is this).

kibot/PcbDraw/plot.py

@@ -56,6 +56,8 @@ default_style = {
         7: '#cc00cc',
         8: '#666666',
         9: '#cccccc',
+        -1: '#ffc800',
+        -2: '#d9d9d9',
         '1%': '#805500',
         '2%': '#ff0000',
         '0.5%': '#00cc11',
@@ -64,6 +66,7 @@ default_style = {
         '0.05%': '#666666',
         '5%': '#ffc800',
         '10%': '#d9d9d9',
+        '20%': '#ffe598',
     }
 }
 
@@ -884,10 +887,15 @@ class PlotComponents(PlotInterface):
         try:
             res, tolerance = self._get_resistance_from_value(value)
             power = math.floor(res.log10()) - 1
-            res = Decimal(int(res / 10 ** power))
+            res = str(Decimal(int(res / Decimal(10) ** power)))
+            if power == -3:
+                power += 1
+                res = '0'+res
+            elif power < -3:
+                raise UserWarning(f"Resistor value must be 0.01 or bigger")
             resistor_colors = [
-                self._plotter.get_style("tht-resistor-band-colors", int(str(res)[0])),
-                self._plotter.get_style("tht-resistor-band-colors", int(str(res)[1])),
+                self._plotter.get_style("tht-resistor-band-colors", int(res[0])),
+                self._plotter.get_style("tht-resistor-band-colors", int(res[1])),
                 self._plotter.get_style("tht-resistor-band-colors", int(power)),
                 self._plotter.get_style("tht-resistor-band-colors", tolerance)
             ]
@@ -914,7 +922,7 @@ class PlotComponents(PlotInterface):
             return
 
     def _get_resistance_from_value(self, value: str) -> Tuple[Decimal, str]:
-        res, tolerance = None, "5%"
+        res, tolerance = None, "20%"
         value_l = value.split(" ", maxsplit=1)
         try:
             res = read_resistance(value_l[0])
@@ -1084,6 +1092,11 @@ class PcbPlotter():
             lib = str(footprint.GetFPID().GetLibNickname()).strip()
             name = str(footprint.GetFPID().GetLibItemName()).strip()
             value = footprint.GetValue().strip()
+            # Look for a tolerance in the properties
+            prop = footprint.GetProperties()
+            tol = prop.get('tol', prop.get('tolerance', None))
+            if tol:
+                value = value+' '+tol
             ref = footprint.GetReference().strip()
             center = footprint.GetPosition()
             orient = math.radians(footprint.GetOrientation().AsDegrees())