`.` after `I` (which has been remapped) does not repeat exactly

[mmalcomson]

We remap the I command.

This is remapped to insert at the logical "beginning of line" which is the start of the command if on a command line.
When using . to repeat that the motion is not included -- so you repeat the previous insert but at the point of the cursor.
This happens when pressing . on either a command line or an output line.

It should repeat at the beginning of the line.