Draw mode of BYPASS EASY symbol not 2525C compliant

[michaeltk3]

The "BYPASS EASY" symbol from the 2525C spec specifies that "Points 1 and 2 determine the graphic’s height and point 3 determines its length." When drawing this feature on the map, the user is able to create a parallelogram shape (see attached image). The drawing mode should restrict the user to a rectangular shape only.

[rsupnekar]

Fix added in branch #293-bypass-easy. To test, build the branch and run test-basic.

From the menu (3 dots in the top right corner), choose:
Test->Draw Menu->Draw MilStd->Draw Tactical Graphic
Enter a name in the dialog. For the Symbol choose:
Tactical Graphics->Mobility/Survivability->Obstacle Bypass->Obstacle Bypass Difficulty->Bypass Easy
When the symbol appears pull one of the extreme control points (not center).
Graphic should stay rectangular