HostFilesUpdate change to include local changes

[hickey]

Changed the process for updating the files downloaded from
pistar.uk. Allows the entire file to be overwritten by a file named
<FILE>-override. Otherwise the file will be downloaded from pistar.uk
and will add <FILE>-prepend and <FILE>-append files to the
downloaded file if they exist. The final operation is to allow a hook
script to modify the file with non-trivial changes. The hook script if
found is named <FILE>.sh. All of these files are located in
~pi-star/etc.

Signed-off-by: Gerard Hickey [email protected]

[hickey]

One or two more notes to go along with this PR.

• The location for the host file overrides is set to ~pi-star/etc in the script. I figured this is a much better place than /root that has been used elsewhere in the script due to the fact that not all the users of pi-star have really good Unix skills. So putting the host file overrides in a location that would make it much easier for users (and even novice users) to find/create made much more sense to me.

• The backup script should probably be updated to also include ~pi-star/etc in the list of files that get backed up and restored.

• Not sure where your documentation is kept, but there should be a paragraph or two to explain how to override the host files. If the documentation is in a repo, then I would be happy to do an initial pass at writing the documentation.

[hickey]

Just a ping to get some feedback and discussion going.

[hickey]

@AndyTaylorTweet Just another ping to kick off the discussion about this proposed change.

I have just rebased against the current master to keep the branch fresh.