keys- and route- files weren't passing the should_ignore_file()
check in dir_changed() because should_ignore_file() was only
taking ifcfg- files into account. Generalize most of the ifcfg name
handling functions so that should_ignore_file() will now handle
all three variants.
Add testcases to ensure that the name handling does what we want
it to, and optimize memory usage of utils_get_ifcfg_name() a bit.
