bootstrap/install.sh: bug fix + better error handling
bootstrap/install.sh: bug fix + better error handling

added missing -passwd change after creating user on MacOS X. This fixes the
problem on MacOS X >= 10.9.x, in which it doesn't recognize the user outside
of the directory service it the password is not set.

changed a few other parts for better readability

devpanel/serverlink,devpanel/serverlink,devpanel/serverlink,devpanel/serverlink,devpanel/serverlink