Added 'ini_subsetting' custom resource type

[kbrezina]

for handling settings which have more arguments such as

JAVA_ARGS="-Xmx192m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/log/pe-puppetdb/puppetdb-oom.hprof "

If you're ok with this approach I can add some rspec tests.

[cprice404]

@kbrezina thanks! this is awesome... I've been wanting to add something like this for a while and haven't been able to find time.

Two things:

1. Can we expose a parameter for overriding the separator between subsettings? Right now you have it hard-coded to work with spaces, but I've seen variables that contain comma-separated values... I think your code would "just work" for those kinds of settings if we could override the separator.
2. as you mentioned--tests.

Again--this is really awesome, thank you.