When using init or install option of slapos.recipe.build to
write python code, the traceback were hard to understand, because
the current line was not included in the traceback.

This put the script in linecache before compiling it, so that in
case of error the problematic line appears in traceback.

There is still the "problem" that the traceback line numbers starts
from the beginning of the script and not the actual line from
buildout profile, but this does not seem feasible to adjust the line
numbers, so let's ignore this.

It is even the recommended recipe for simple download.

The purpose is to replace colletive.recipe.shelloutput

/reviewed-on !11

An unrelated change is about develop mode: the behaviour was simplified to do nothing if a working copy already exists.

TODO: handle removal of submodules

/reviewed-on !7

Note that we don't change the URL for BAD_GIT_REPOSITORY as we need them
to return 500 while trying to clone. If we use Nexedi Gitlab repo for
non-existing repo, we get redirected to login page. Hence, we keep using
git.erp5.org for `repo/nowhere`.

/reviewed-on !6

This recipe alters a system perl ( or perl installed by another buildout
recipe ), which is not consistent with the independence of parts we are
trying to achieve in order to be able to cache and share parts.

SlapOS comonents now expose a `perl-CPAN-package` macro that should be
used for consistency. See slapos!341

/reviewed-on !4

- No more limit on the number of preseed parameters, by placing a preseed.cfg
  file inside the initrd, instead of passing them all via the command line.
  The kernel is usually limited to 32 parameters and it panics when there are
  too many.

- Dist-specific options.

- Recognize preseed aliases.

- late-command is run with '/bin/sh -e' and it must exit with EX_OK (0),
  otherwise the installer stops.

This reverts commit 9bd1e7e7.
What about test nodes ??
Why treating unpushed commits differently ?

commited-but-not-pushed changes will be lost.

Because it is the most important thing now in this egg.

Both are compatible.

It allows to easily extend an existing section

If 'ignore-ssl-certificate' option is true, gitclone will not check
if ssl certificate are valid when fetching.

This reverts commit 0877f72d.