build-sys: use gcc as our compiler of choice
build-sys: enable PAM support
build-sys: utilize compiler flags handed to us by rpmbuild
doc: add configuration samples
build-sys: don't hardcode LIBDIR, but set it according to the target platform
scritps: use change_resolv_conf function

Don't handle /etc/resolv.conf manually, but use a helper function from
initscripts. Also change path where we save DNS servers supplied by peer while
we are at it.

Resolves: #132482
build-sys: don't strip binaries during installation

We don't want that when building rpms. rpmbuild does final stripping of binaries
for us and generetes debuginfo rpm.
build-sys: use prefix /usr instead of /usr/local
pppd: introduce ipv6-accept-remote
build-sys: enable CBCP

Resolves: #199278
build-sys: don't put connect-errors log to /etc/ppp/

Resolves: #118837
pppd: we don't want to accidentally leak fds
everywhere: O_CLOEXEC harder
everywhere: use O_CLOEXEC when creating socket
pppd: move pppd database to /var/run/ppp

Resolves: #560014
rp-pppoe: add manpage for pppoe-discovery
pppd: rebase EAP-TLS patch v0.994
scritps: fix ip-up.local sample

Resolves: #613717
sys-linux: rework get_first_ethernet()

We can't assume that host has ethernet NIC named "eth0". Rather than guessing we
better ask udev. We iterate over symlinks symlinks in /sys/class/net and
for each device we determine if it is ethernet device and additionally we query
udev database for sub-type of the device. If we find PCI or USB device which has
ethernet datalink type and appropriate sub-type we return its name. If don't
succeed in determining more information about device we will return "good
enough" device which in turn is first device with ethernet datalink type.

This commit replaces ppp-2.4.5-eth.patch.

Resolves: #682381
pppd: put lock files in /var/lock/ppp

Resolves: #708260