Plain text editors: nano in basic, emacs and vim in high-level

While a project is under development, the raw analysis software are not the
only necessary software in a project. We also need tools to all the edit
plain-text files within the Maneaged project. Usually people use their
operating system's plain-text editor. However, when working on the project
on a new computer, or in a container, the plain-text editors will have
different versions, or may not be present at all! This can be very annoying
and frustrating!

With this commit, Maneage now installs GNU Nano as part of the basic
tools. GNU Nano is a very simple and small plain text editor (the installed
size is only ~3.5MB, and it is friendly to new users). Therefore, any
Maneaged project can assume atleast Nano will be present (in particular
when no editor is available on the running system!). GNU Emacs and VIM
(both without extra dependencies, in particular without GUI support) are
also optionally available in 'high-level.mk' (by adding them to
'TARGETS.conf').

The basic idea for the more advanced editors (Emacs and VIM) is that
project authors can add their favorite editor while they are working on the
project, but upon publication they can remove them from 'TARGETS.conf'.

A few other minor things came up during this work and are now also fixed:

 - The 'file' program and its libraries like 'libmagic' were linking to
   system's 'libseccomp'! This dependency then leaked into Nano (which
   depends on 'libmagic'). But this is just an extra feature of 'file',
   only for the Linux kernel. Also, we have no dependency on it so far. So
   'file' is not configured to not build with 'libseccomp'.

 - A typo was fixed in the line where the physical core information is
   being read on macOS.

 - The top-level directories when running './project shell' are now quoted
   (in case they have special characters).

0 files changed, 0 insertions, 0 deletions