Revert "Put in some machinery to return non 0 for commands that failed. Not wonderful."

This reverts commit 3c7e07ca3b9dfd2b107303dcd9615538669eec4d.

3c7e07ca... lead to rc _always_ having a non-zero exit code for the following options: --code-completion-enabled, --is-indexing, --has-filemanager.

Setting the exit code to non-zero to indicate failure would be a good thing. Consider making the determination of success/failure of a command the responsibility of the command's class.
[Cosmetic] clean-up code in last commit.