Fix for scrolloff vim setting

[froloffw7]

When scrolloff vim variable set, the cursor control codes 'H' and 'L' doesn't move cursor to the top and bottom lines of the screen. I suggest small minimap.py fix for this case

# Save scrolloff value and set it to 0
+ so = vim.eval("&scrolloff")
+ vim.command(":set scrolloff=0")
  vim.command("normal! H")
  topline = src.cursor[0]
  vim.command("normal! L")
  bottomline = src.cursor[0]

...

# Restore scrolloff
  src.cursor = cursor
+ vim.command(":set scrolloff=%s" % so)

[severin-lemaignan]

hi! thanks for the suggestion. Can you make a PR, please, and I'll merge it?

[froloffw7]

This is the changed file.

minimap.py.gz