Split TooltipProvider into its own file and renamed from FSharpLanguageItemTooltipProvider to FSharpTooltipProvider
Added LoggingService based logging for ResolverProvider and TooltipProvider
Upgraded to FCS version 48

Removed depreciated `DefaultMonospaceFontDescription` which is now
`MonospaceFont`
Added changes from InterfaceStubGenerator
Merge pull request #559 from 7sharp9/master

Upgraded to FCS version 48
Ensure that only dll references are included in pcl search path

Fixes #562
Merge pull request #563 from 7sharp9/master

Ensure that only dll references are included in pcl search path