Updates to Element Creation

Most element creation has been fleshed out.  The face based families is
still a little off, but otherwise seems to work well.  You can now
create based on:
1. Origin Point
a. any standard non-hosted family.
b. any hosted family (wall, floor, ceiling, or roof)
c. face based families (needs work).
2. Single Curve
a. Linear Curve (line based families, struct columns, walls)
b. Arc Curve (struct beams, walls)
3. Closed Planar Curve (arc, linear, spline)
a. Horizontal (floor, roof)
c. Vertical (walls)

Still have not implemented Modification/Updates or unit handling (Revit
API defaults to feet).