Merge pull request
#950 from minrk/startup
Add directory for startup files, enabling users to add local configuration more simply without having to know how the config system works much at all.
Now, `profile/startup` dir is checked for files, and they are run prior to explicit exec_code and exec_files.
A short README is added to the dir explaining how they work, and a short paragraph is added to the docs, in both the interactive tutorial and config overview.