Testcases: run them faster.

Simple trick: raise the feedrate, no need to care about a milling
bit when running a simulation. This reduces simulated time and as
such, duration of the simulation (by about 50%).

Also remove G-code which was never executed because simulations
are chopped at 1 minute of simulation time and smooth-curves.gcode
took about 1.5 minutes.

Step pulse measurements remain about the same:

  ATmega sizes               '168   '328(P)   '644(P)     '1280
  Program:  17944 bytes      126%       59%       29%       14%
     Data:   1920 bytes      188%       94%       47%       24%
   EEPROM:     32 bytes        4%        2%        2%        1%

  short-moves.gcode statistics:
  LED on occurences: 888.
  LED on time minimum: 202 clock cycles.
  LED on time maximum: 380 clock cycles.
  LED on time average: 232.092 clock cycles.

  smooth-curves.gcode statistics:
  LED on occurences: 22589.
  LED on time minimum: 194 clock cycles.
  LED on time maximum: 423 clock cycles.
  LED on time average: 254.425 clock cycles.

  triangle-odd.gcode statistics:
  LED on occurences: 1636.
  LED on time minimum: 220 clock cycles.
  LED on time maximum: 380 clock cycles.
  LED on time average: 245.575 clock cycles.

testcases/smooth-curves.gcode

@@ -1,10 +1,10 @@
 G21
 G90
-G0 X69.0909 Y11.6477 Z1.0
+G0 X69.0909 Y11.6477 Z1.0 F6000
 G4
 M106 S255
 G1 Z-0.20 F75.0
-G1 X72.727 Y12.613 F400.0
+G1 X72.727 Y12.613 F4000.0
 G1 X71.805 Y9.726
 G1 X70.575 Y7.201
 G1 X69.035 Y5.039
@@ -88,82 +88,6 @@ G1 X69.133 Y10.243
 G1 X69.090 Y11.647
 G1 X69.090 Y11.647
 G0 Z1.0
-G1 X127.272 Y14.545
-G1 Z-0.20 F75.0
-G1 X127.496 Y18.160 F400.0
-G1 X128.167 Y21.278
-G1 X129.286 Y23.899
-G1 X130.852 Y26.022
-G1 X132.439 Y27.365
-G1 X134.190 Y28.323
-G1 X136.104 Y28.899
-G1 X138.181 Y29.090
-G1 X141.592 Y28.856
-G1 X144.268 Y28.153
-G1 X146.209 Y26.981
-G1 X147.414 Y25.340
-G1 X148.148 Y23.284
-G1 X148.671 Y20.866
-G1 X148.986 Y18.085
-G1 X149.090 Y14.943
-G1 X149.092 Y12.389
-G1 X149.098 Y10.127
-G1 X149.106 Y8.157
-G1 X149.119 Y6.477
-G1 X148.884 Y5.028
-G1 X148.153 Y3.75
-G1 X146.924 Y2.642
-G1 X145.198 Y1.704
-G1 X143.279 Y0.958
-G1 X141.470 Y0.426
-G1 X139.770 Y0.106
-G1 X138.181 Y0
-G1 X135.855 Y0.234
-G1 X133.764 Y0.937
-G1 X131.907 Y2.109
-G1 X130.284 Y3.75
-G1 X128.966 Y5.831
-G1 X128.025 Y8.323
-G1 X127.460 Y11.228
-G1 X127.272 Y14.545
-G1 X127.272 Y14.545
-G0 Z1.0
-G0 X130.909 Y14.545
-G1 Z-0.20 F75.0
-G1 X130.981 Y11.988 F400.0
-G1 X131.200 Y9.772
-G1 X131.564 Y7.897
-G1 X132.073 Y6.363
-G1 X132.892 Y5.170
-G1 X134.183 Y4.318
-G1 X135.946 Y3.806
-G1 X138.181 Y3.636
-G1 X140.786 Y3.806
-G1 X142.748 Y4.318
-G1 X144.067 Y5.170
-G1 X144.744 Y6.363
-G1 X145.055 Y7.908
-G1 X145.277 Y9.815
-G1 X145.410 Y12.084
-G1 X145.454 Y14.715
-G1 X145.410 Y17.198
-G1 X145.277 Y19.360
-G1 X145.055 Y21.203
-G1 X144.744 Y22.727
-G1 X144.067 Y23.920
-G1 X142.748 Y24.772
-G1 X140.786 Y25.284
-G1 X138.181 Y25.454
-G1 X135.946 Y25.285
-G1 X134.183 Y24.779
-G1 X132.892 Y23.936
-G1 X132.073 Y22.755
-G1 X131.564 Y21.230
-G1 X131.200 Y19.353
-G1 X130.981 Y17.125
-G1 X130.909 Y14.545
-G1 X130.909 Y14.545
-G0 Z1.0
 G4
 M106 S0
 M2