Merge c138c5ff44 and later to vim

[dbarnett]

Our changes to add a vroomText syntax group with @Spell and later haven't been merged into vim's built-in runtime files yet. After trying the changes out for a while, we should get the patch relicensed for the vim license and get it merged into vim.

[dbarnett]

Wow, we still haven't merged this after almost a year, have we?