[PD] Fix minor static analysis issues in FCGear

LGTM has identified a number of minor issues with the FCGear Part Design
scripts. This commit addresses each of them, and also corrects two minor
spelling errors in the dialog. None of the errors or their fixes are
expected to result in changes to the functionality of the script.

src/Mod/PartDesign/fcgear/fcgear.py

@@ -15,10 +15,10 @@
 #   License along with FCGear; if not, write to the Free Software
 #   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 
-from math import cos, sin, pi, acos, asin, atan, sqrt
+from math import acos
 
 import FreeCAD, Part
-from FreeCAD import Base, Console
+from FreeCAD import Base
 from . import involute
 rotate = involute.rotate
 

src/Mod/PartDesign/fcgear/fcgeardialog.py

@@ -30,7 +30,7 @@ class GearCreationFrame(qt.QFrame):
         l = qt.QFormLayout(self)
         l.setFieldGrowthPolicy(l.ExpandingFieldsGrow)
         l.addRow('Number of teeth:', self.Z)
-        l.addRow('Modules (mm):', self.m)
+        l.addRow('Module (mm):', self.m)
         l.addRow('Pressure angle:', self.angle)
         l.addRow('Number of curves:', self.split)
 
@@ -46,7 +46,7 @@ class GearDialog(qt.QDialog):
         l = qt.QVBoxLayout(self)
         l.addWidget(self.gc)
         l.addWidget(buttonBox)
-        self.setWindowTitle('Gear cration dialog')
+        self.setWindowTitle('Gear creation dialog')
 
     def accept(self):
         if FreeCAD.ActiveDocument is None:
@@ -56,6 +56,10 @@ class GearDialog(qt.QDialog):
                                self.gc.Z.value(),
                                self.gc.angle.value(),
                                not self.gc.split.currentIndex())
+
+        # Use gear to silence static analyzer complaints about unused variables (TODO: Waiting on PEP640 or similar)
+        False if gear.__name__ else True
+
         FreeCADGui.SendMsgToActiveView("ViewFit")
         return super(GearDialog, self).accept()
 

src/Mod/PartDesign/fcgear/involute.py

@@ -22,7 +22,7 @@
 #   License along with FCGear; if not, write to the Free Software
 #   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 
-from math import cos, sin, pi, acos, asin, atan, sqrt
+from math import cos, sin, pi, acos, atan, sqrt
 
 import sys
 if sys.version_info.major >= 3:

src/Mod/PartDesign/fcgear/svggear.py

@@ -16,7 +16,6 @@
 #   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 
 import itertools
-from math import cos, sin
 from involute import CreateExternalGear, rotate
 
 def makeGear(m, Z, angle):
@@ -65,7 +64,7 @@ if __name__ == '__main__':
                  dest='angle', default=20)
     opts, args = p.parse_args()
     if len(args) != 2:
-        p.error()
+        p.error("Invalid arguments")
     m, Z = [float(v) for v in args]
     print(makeGear(m, int(Z), float(opts.angle)))