Removed dead code, old comments, unused open statements
Use UTF-8 when talking to FSI.
Fixes #554
Merge pull request #555 from rojepp/fix_encoding

Use UTF-8 when talking to FSI.
Split TooltipProvider into its own file and renamed from FSharpLanguageItemTooltipProvider to FSharpTooltipProvider
Added LoggingService based logging for ResolverProvider and TooltipProvider