Fix naming of IEEE 802 working groups

Use 'wpa' to refer to the 802.11i and 802.1x client side software
(wpa_supplicant) in general.
Don't rebuild the manpages on install

Only (forcefully) rebuild them when generating a source tarball.
This is an addendum to 9b500.
Allow group-accessible tuntap devices

The tuntap connection type requires both a User and a Group to be
defined. However, when configuring a tuntap device in the kernel, the
device's uid and gid must both match for someone to be able to use the
device. The only way to create a tuntap device accessible to a group of
users is therefore to avoid specifying the user argument to
"ip tuntap add".

Reported by: A Web
Updated man page to include pppoe and mobile_ppp

Removed unnecessary options from example connection.
add command to turn modem on, fix pin command
Small review of PPP related connections

The most important change is that we now bring the interface down
correctly in pppoe_down.
Management related changes

- add back to 'base' group
- add .gitignore that ignores build results
Small review of PPP related connections (take 2)

The previous take did not contain the stuff that initially motivated
rewriting the quoting function.
The code of both PPP connection types is still sub-par, but at least
functionally, it is a little better now.
1.0 release updates
Remove the last traces of netcfg
Use pkg-config to obtain the systemd system unit directory

This ensures the units are installed correctly if systemd is installed
in an alternate location like /lib/systemd. Idem for the location of
profile-based units.

Based on a proposal by: Mike Gilbert <floppym@gentoo.org>
Improve array handling

When interpreted as an array, the empty string represents a 1-element
array consisting of the empty string. This is actually very reasonable.

Reported by: Thomas Bächler <thomas@archlinux.org>
Added netctl-auto detection
More consistent approach to output
Make a directory for a unit file link before creating the link itself.

The '/etc/systemd/system/multi-user.target.wants' directory does not
necessarily exist before netctl is invoked.
Typo in a sample profile
Flush the interface configuration in ip_unset instead of bring_interface_down.

When switching networks in auto.action, the addresses are not flushed. This
is especially problematic with stateless ipv6 autoconfigutation, as invalid
IPs may stay around until their (potentially very long) lifetime has expired.

bring_interface_down is always called after ip_unset everywhere else, so
this change does not affect anything else.

V2: Make sure not to flush the link local address.
Restrict dhcpcd to IPv4

By default, dhcpcd requests leases for both versions of IPv6.
In the past, dhcpcd did not support IPv6, so this commits restores old
behavior.
Properly check existence of a connection type.

Substituting "/dev/null/nonexistent" for an empty $Connection,
of course, does generally work, but is somewhat ugly (esp. in that
the string is appended to $CONN_DIR, so the resulting path may
theoretically exist).

Instead, substitute an empty string for the complete path if $Connection
is empty: an empty string can never be readable.

Signed-off-by: Ivan Shapovalov <intelfx100@gmail.com>
Rewording some lines regarding exit codes