Geometry with a small number of rotations in phi direction (#9)

* take care corner cases of small # of rotations in phi

* estimate numx & numy on-the-fly instead of saving them in CellID (overflow of field with small # of rotations)

* fix readouts

Author: SanghyunKo

Detector/DRcalo/compact/DRcalo.xml

@@ -703,7 +703,7 @@
     <readout name="DRcaloSiPMreadout">
       <segmentation type="GridDRcalo"/>
       <!-- Mendatory to use the first 32 bits for tower infos & the last 32 bits for fiber/SiPM infos -->
-      <id>system:5,eta:-8,phi:9,xmax:32:6,ymax:6,x:6,y:6,c:1,module:2</id>
+      <id>system:5,eta:-8,phi:9,x:32:6,y:6,c:1,module:2</id>
     </readout>
   </readouts>