strongswan: Updated (4.6.3 -> 4.6.4)
openvpn: Updated (2.2.2 -> 2.3.0)
openvpn: improved to let configure find the 'ip' command

Note:

This is particulary needed when cross-compiling openvpn but is also
useful if a custom prefix is used for iproute2.
libprelude: changed to build at cross-stage on request
libprelude: improved to disable python support if python is not installed effectively

Note:

This change needs to be introduced because when cross-compiling configure
detects the python installation from the host which leads to enabling
python support even if there is no python installed in the target.
freeradius: changed to build at cross stage on request
freeradius: fixed installation when cross-compiling
strongswan: Updated (4.6.4 -> 5.0.1)
strongswan: fixed to use the linux kernel headers installed by the linux-header package
strongswan: changed to build at cross stage on request
strongswan: fixed to use the right path for {C,CPP,LD}FLAGS for openldap when cross-compiling
openldap: Updated (2.4.32 -> 2.4.33)
openldap: changed to build at cross stage on request
openvpn: changed build prio (186.700 -> 200.000)
openvpn: fixed to disable pam auth plugin if pam is not installed effectively

Note:

Starting with openvpn 2.3.0 there seem to be changes how plugins are enabled
and there are configure switches now for disabling the shipped plugins.
openvpn: removed obsolete code for building plugins

Note:

Starting with openvpn 2.3.0 there seem to be changes how plugins are enabled
and there are configure switches now for disabling the shipped plugins.
vblade: changed to build at cross stage on request
aoetools: changed to build at cross stage on request
execline: fix whitespacing in conf file
s6: Updated (0.16 -> 0.17)