Indents documentation tests with blocks for hygiene.
Adds foldl and foldr templates to sequtils.
Removes executable bit for text files.
Merge pull request #364 from gradha/pr_fixes_unix_file_permissions

Removes executable bit for text files.
Merge pull request #362 from gradha/pr_adds_fold_templates_to_sequtils

Adds fold templates to sequtils
Separate out install/uninstall script generation

- Add a new command to koch: instscripts, which creates the install
and uninstall scripts, update niminst to match, mark scripts executable.
- Don't track install scripts in Git.