Previously if "$rootok" = 1, parsing of netroot command line arguments
was skipped. For multiple netroot arguments, all parse scripts have to
run.
Previously only the first netroot argument was taken into account for
the parsing scripts. Now every netroot argument is processed.
As with other netroot boot arguments ip= lines should be parsed and
checked. Having this has the advantage that other cmdline scripts
can tell the ip= parser if dhcp or ip=:srv:... is needed, like
parse-root.sh (renamed dhcp-fallback) or parse-nfsroot do.
The nfs test-suite has one check which uses static ip lines, but
the autoconf param is wrong. Fixed this as well.