Complete SpecFetcher documentation
Complete SourceList documentation
Complete SourceFetchProblem documentation
Complete Gem::Source::Vendor documentation
Complete Source::SpecificFile documentation
Completed Source::Local documentation
Fix SpecificFile after doc change

The parentheses were removed, but this breaks as a bare * in the
arguments list requires parentheses for disambiguation.

So use a named variable.
Complete Source::Installed documentation
Git sources come before all but installed

This matches the behavior of bundler (I think).
Vendor sources come before installed sources

Seems natural, but I did not check bundler.