Remove left scrollbar on win32

The left scrollbar repositions vim's main window when I create a vsplit
in Win32. I don't think this behavior occurs on Linux. The left
scrollbar lets you have independent scrollbars for each window. Instead,
I have one global scrollbar for whichever window is active.

Update comment for disabling tabline to indicate how it breaks behavior.
Prevent slowness when using completion

When editing large files, ins-completion can be very slow if
foldmethod=syntax. Use foldmethod=indent by default instead.
Use FastFold to work around foldmethod=syntax bug

Instead of abandoning foldmethod=syntax (which is usually the most
effective folding, add FastFold which makes folds only recalculate on
save.

Disable the fold recalculate map (I can just save). Instead, recalculate
on redraw. That's usually what I bang on when things aren't working.
Convert map -> noremap

Fix several cases where I was carelessly using map.

nmap Y was partly intentional -- so it would use yankstack, but it gets
remapped by sensible and fixed in after/plugin/sensible.vim
sub: Improve notgrep's vim to perl translation

Tested with wonders like:
    \(has_\|con_\)state\(graph\)\? =
    \v(has_|con_)state(graph)? =