up to 0.9.0

up to 0.9.0

keep on using "workaround" for linking directly with lua module.
upstream dropped it in:

https://github.com/neovim/neovim/commit/da0c66bcddbe4e6ebc72357c9f6c5de75e176744

without explaining how "correctly packaged libluv" looks like exactly.
libluv built with lua54 is incompatible with neovim built against
lua51/luajit so I guess upstream idea is that libluv should be forced
"their way". if libluv had a chance of easily installing parallel
libraries for different lua versions (different sonames, different
pkgconfig files) and neovim could select between them it would be
feasible but it's not available so just revert the commit.