This patch adds a new authorised_value_category.is_system boolean/tinyint(1)
DB field.
Name 'is_system' is coming from existing tables account_credit_types and
account_debit_types and should not be discussed here (if you disagree
fill a new bug report and deal with naming issue separately)
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net> Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de> Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>