support source file from command line
refactor filter tests a bit, now use a parent test

another filter for apache httpd like conf
rewrite the properties filter

for keeping order, so do not use build in Properties
also, add a new abstract LineBasedContentFilter
throw away apache conf content filter

it turned out it's too complicated so I don't want to support
it's advised to use Env Var in httpd.conf, and we can filter sh vars