Add version tags alongside commit hashes in output

- tools.json now has both "version" (tag) and "hash" (commit) fields
- Output format: toolname@version [hash] (in duration)
- Update tool fetches and stores both version and hash
- Fix .gitignore to not exclude cmd/update directory

.gitignore

@@ -1,6 +1,6 @@
 # Binaries
-gosetup
-update
+/gosetup
+/update
 *.exe
 
 # Test binaries