Do the depmod in the kernel-install hooks, so hooks can produce/install
kernel modules and be part of the depmod.
Also move the basic boot loader entry creation and removal to a
plugin script.
If PRETTY_NAME is not defined in /etc/os-release, fallback to
PRETTY_NAME="Linux $KERNEL_VERSION".
Add documentation for everything in the man page.
Everything which is an absolute filename marked with <filename></filename>
lands in the index, unless noindex= attribute is present. Should make
it easier for people to find stuff when they are looking at a file on
disk.
Various formatting errors in manpages are fixed, kernel-install(1) is
restored to formatting sanity.
