Don't verify nf_conntrack for br_netfilter

add solution message if kubeadm binary is not executable on linux

We need to make sure that the br_netfilter kernel module
has been loaded, when using non-Docker container runtimes.

But the code was verifying the nf_conntrack kernel module
instead, so it could still cause the "not loaded" error.

[ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]

Kernel with CONFIG_IKHEADERS for BPF tools on Kubernetes

BCC tools need to have access to kernel headers. It can be done either
by installing linux-headers packages or by having a kernel compiled with
CONFIG_IKHEADERS so that enough information can be retrieved via
/sys/kernel/kheaders.tar.xz.

BCC tools are used in Inspektor Gadget, a collection of tools for
developers of Kubernetes applications. I would like Inspektor Gadget to
support Minikube.

CNI: Update CRIO netconfig with matching subnet

add verification for enabling ingress, registry and gvisor addons

Support prerelease versions of podman binary

Fix bug in FailFastError and add unit test

It was trying to parse the newline character

Since FailFastError was just another `error`, all errors were technically `FailFastErrors`.

This code makes `FailFastError` a struct which implements the error interface, so that now errors can be distinctly identified as `FailFastError`'

Also added a unit test to prove that this works now.

Check for iptables file before determining container is running

apiserverHealthz: wait up to 8s before declaring failure

Add --cni flag (replaces --enable-default-cni), fix --network-plugin handling

docker driver on linux: Give warning if overlay module is not enabled