Add default value for v_speed argument in DragScalar{N}

[eliasdaler]

This makes API consistent with typed Drag<T><N> widgets which allow to not specify v_speed manually

[eliasdaler]

Another thing I've found is that a default format string for generic "float" type is "%f", while most functions default to "%.3f", which is nice. (right now I'm getting 6 decimals after the floating point when I use DragScalar, which is not nice)
Maybe it should get fixed here too?

[ocornut]

Thank you, merged.

Another thing I've found is that a default format string for generic "float" type is "%f", while most functions default to "%.3f", which is nice. (right now I'm getting 6 decimals after the floating point when I use DragScalar, which is not nice)
Maybe it should get fixed here too?

I think it would indeed be good to change this to "%.3f". It makes that DataType info array carry a little more responsibility than necessary but overall make things more consistent. Broken by 3e80874
I'll change it now.