pvl.hosts: improve HostExtension support enough to move boot= into pvl.hosts.dhcp
## Output calling function's name.
function func_caller {
caller 1 | cut -d ' ' -f 2
}
## Test if given symbol is a function
# XXX: tests if it is anything atm?
function func_test {
type -t "$1" > /dev/null
}
## Get current unix (utc) timestamp
function unix_time {
date +'%s'
}