Width of rename window not configurable

[cangermueller]

Hi!

1. The width of the rename window is hard-coded here and often not wide enough to fit long (function, etc) names.
   Can the width be made configurable or adjusted to the name that is renamed?

2. The original name is erased when starting to type in the window. I.e., I cannot jump to the end and add a few characters to the existing name. E.g. for renaming foo -> foo2 requires typing "foo2" instead of just appending "2" to "foo". Can this be changed by a) placing the cursor at the end of the existing name in the window (now it's at the beginning), and b) by not erasing the existing name when starting to type?

Thanks!