7.1.0

Update FSAC to 0.56.12 for these changes
Removed unused FAKE configuration settings and handler code
Massively improve error messages when dotnet isn't found (thanks @MangelMaxime!)
Improve FSI management (thanks @MangelMaxime!)
Fix solution explorer icons for solutions and projects (thanks @MangelMaxime!)
Fix logic in 'add file to project' (thanks @MangelMaxime!)
Fix hangs on double-backticked identifiers (thanks @MangelMaxime!)