MPD.Internal: enable line buffering for conn handle
MPD.Internal: code golf manager operations
Merge branches 'line-buffer' and 'refactor-manager' into pu

Conflicts:
	src/MPD/Internal.hs
MPD.Internal: assume flush is unnecessary with line buffering
Merge branch 'line-buffer' into pu
Merge branch 'line-buffer' into next
Merge branch 'refactor-manager' into next
Merge branch 'next' into pu