sketch_template: make prefixes more logical
motd: wait until the path is set to use it
sysctl: sixify
sketch_template: no_x_prefix is useless
packages_installed: sixified
packages_installed: sixified.1
Redmine#4278: packages_installed: add a from_file entry point
Redmine#4278: packages_installed: add a from_url entry point
Redmine#4280: packages_removed: sixify and add from_file entry point
Redmine#4896: DCAPI: allow REPO in #@include to mean "repo you're being installed into"
Redmine#4896: use REPO instead of relative path
Redmine#4301: syslog: sixify
Fixed error checking during installation.
First iteration of sketchify for 3.6

Major restructuring of the code. For now the functionality remains
basically the same: `sketchify file.cf`, and answer the interactive
prompts. The restructuring enables future functionality, such as using
sketchify to update existing sketches.

New hidden feature: `sketchify file.cf script.txt`, lines will be read
from `script.txt` and used to automatically answer the prompts. Useful
for testing.
Disabled `run` and fixed `generate`

The `run` command is disabled for now due to changes in the API. Will be
fixed. The `generate` command was updated to account for latest changes
in the API.