Add new artifacts and binary directories in gitignore files.

[sdimitro]

After a build doing a git status show the following:

$ git status
warning: could not open directory 'live-build/variants/internal-qa/binary/var/cache/apt/archives/partial/': Permission denied
warning: could not open directory 'live-build/variants/internal-qa/binary/var/cache/ldconfig/': Permission denied
warning: could not open directory 'live-build/variants/internal-qa/binary/export/home/cli/.ssh/': Permission denied
warning: could not open directory 'live-build/variants/internal-qa/cache/bootstrap/root/': Permission denied
warning: could not open directory 'live-build/variants/internal-qa/cache/bootstrap/var/cache/ldconfig/': Permission denied
On branch migration-03
Untracked files:
  (use "git add <file>..." to include in what will be committed)

        live-build/artifacts/internal-qa.gcp.tar.gz
        live-build/artifacts/internal-qa.migration.tar.gz
        live-build/artifacts/internal-qa.upgrade.tar.gz
        live-build/variants/internal-dcenter/binary/
        live-build/variants/internal-dev/binary/

nothing added to commit but untracked files present (use "git add" to track)