core: Fix relative configuration paths on commandline

The current directory is reset at startup to the configuration path,
mostly as a matter of hygiene. If using a relative path from the
commandline, paths derived from it need to be relative to the new
current directory instead.
translation: Untranslate tor-related internal errors

There is no value in translating technical error strings; many of these
aren't shown to users, and when they are, their translated form won't be
of any more use. It just adds burden on translators.