This commit adds two separate modes for defining angular spacing between
elements in the PD's Polar Pattern:
1. Overall Angle - which behaves exactly like it behaved before,
2. Offset Angle - which allows user to specify separation angle between
consecutive elements.
This change is analogue to that introduced for LinearPattern in previous
commits.
This commit adds support for two separate modes of defining distance
between elements in PD's Linear Pattern.
1. Overall Length - which works exactly like it works before,
2. Spacing - which allows user to explicitly define distance (offset) between
features.
- Helix: the property Turns has the App::PropertyFloatConstraint thus also the pointer to it must have the same property
- LinearPattern and Helix: make constraints static class member (forgot this in commit 3704ad68)
- Draft: make the constraint const
- PolarPattern and LinearPattern assure that the header file is loaded at last to avoid potential troubles
- remove StdDirection,StdAxis and StdMirrorPlane properties
- support sketch H_Axis, V_Axis, N_axis as valid references in patterns
- polish reference selection gui (unified for standard axes and custom references)
