fixes to not to rely on dkms anymore, kernel v5.8

[zappacor]

Created a new build script (zappacor-build-5.8.18.sh) plus its companion files.
You should add the Debian packaging part to it and you're gonna be good to go.
I'll check for kernels v5.9 and get back to you with other files if needed (that's the main reason why I added 5.8.18 references to the names and almost everywhere)

[zappacor]

An improvement that forgot to add yesterday: for the .config file, I worked on elegant ways to get it (so no need to copy it from any repo) and came up with this:

#################################################################
################## CONFIG AND BUILD THE KERNEL ##################
#################################################################
ZAPPACOR_DEFCONF=`readlink -f $ZAPPACOR_DEFCONF`
cd $ZAPPACOR_WORKDIR/linux-$KERNEL_VERSION
make clean
sed 's/CONFIG_LOCALVERSION=.*/CONFIG_LOCALVERSION="-zappacor"/' /boot/config-`uname -r` >.config
make olddefconfig
# Build it
time make -j$((`grep -c ^processor /proc/cpuinfo`*2)) all
cd -

Also, for manual installation instead of .deb packages creation, have to strip (see INSTALL_MOD_STRIP=1 additions) the files on installation (not doing so makes initrd so huge it can't even be loaded on boot):

######################################################################
################## LOCAL COMPUTER TEST/INSTALLATION ##################
######################################################################
cd $ZAPPACOR_WORKDIR/linux-$KERNEL_VERSION
# Should check if the headers are really needed or not (guess they're not)
#   make headers ; make headers_install
make INSTALL_MOD_STRIP=1 modules_install
make INSTALL_MOD_STRIP=1 install
cd -
# Need this for the Broadcom WiFi on my *HP laptop* to work (these following steps are *not* related to any Mac at all)
wget -c -P $ZAPPACOR_DOWNLOADS https://launchpad.net/ubuntu/+source/bcmwl/6.30.223.271+bdcom-0ubuntu7/+build/20102161/+files/bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu7_amd64.deb
apt install $ZAPPACOR_DOWNLOADS/bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu7_amd64.deb