possibly make extern dir auto added to file paths

[iainctduncan]

Possible enhancement: add extern dir automatically to search path, as if user has added it to the file prefs or used a [declare -path s4pd].

Not sure if this will be done or not, part of me thinks the user needs to know how search paths find scm files before they use s4pd anyway, or they will be get frustrated, so having to figure this out on install is not a bad thing. Also, if we add hackable versions (adding to C) as planned, a user may have multiple versions of s4pd, so explicit paths may be important. I need to think about it some more.