Adds aliases

"add" is an alias for "install"
"uninstall" is an alias for "remove"
"ksp use" is an alias for "ksp default"
Another minor typo, shows only in debug messages
Merge pull request #585 from hakan42/MinorTypoInDebugOutput

Another minor typo, shows only in debug messages
IsKspDir should not log a error in the false case.
This avoids it by adding a precondition to the call to DetectVersion which logs the error.
Closes #373.
Merge pull request #579 from Ippo343/Aliases

Adds command line aliases
Merge pull request #587 from RichardLake/ErrorInReadmeFile#373

IsKspDir should not log a error in the false case.