Where is the common-sense button that aligns curve handles and resets them? All I want to do is make a simple spline IK. Apparently this is impossible because in order to construct one, I very expectedly have to move the curve handles. Moving the curve vertices automatically misaligns the handles so that they don't point towards each other to keep a straight line, even though they should. 

I tried all kinds of selection to cursor and snapping techniques, none of which work because the lengths of the handles are no longer at their default value. How can I get blender to do what it is supposed to and construct a simple, straight segment of merely two handles pointed towards each other at their default length?
Edit Mode:


A Select all
V V Convert control points to Vector


With just 2 points, this will produce the straight line I think you're looking for? I do this to every Bezier curve on creation..  it just helps get off to a known, 'neutral' start.

After that, you might want to W S subdivide, (or, in 2.8 right click > Subdivide) to make more in-line vertices.