Manually managing temp files into fixes variables (EASYRSA_TEMP_FILE_*),
can result in errors like in build_ca that reused EASYRSA_TEMP_FILE_3.
A temporary directory simplify the cleanup.
A configurable directory for temp files (var EASYRSA_TEMP_DIR) also
allows the user to define a different temporary directory. This is
important for devices using flash disks that have limited number of
writes.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
6ecb6f489e