interfaces: disable the use of ioctl for bridges

interfaces: disable the use of ioctl for bridges

ioctl for bridges are not needed since 2.6.14. Moreover, they don't
play well with some drivers and they have an undefined behaviour in
32/64 bits mixed environment. Instead, we use sysfs.

Moreover, we define a new configure option `--enable-oldies` which
allows the use of those ioctl. Currently, anything not needed with a
2.6.18 kernel will be declared as oldies and disabled by default.