vm.args support for node_package

[joedevivo]

So, the output in a cuttlefish world looks like this:

➜  riak git:(jd-cuttlefish) ✗ ./rel/riak/bin/riak console
egrep: /Users/joe/dev/basho/riak/rel/riak/bin/../etc/vm.args: No such file or directory
grep: /Users/joe/dev/basho/riak/rel/riak/bin/../etc/vm.args: No such file or directory
Node 'riak@127.0.0.1' not responding to pings.
11:56:27.914 [info] Application lager started on node nonode@nohost
11:56:27.914 [info] No app.config detected in /Users/joe/dev/basho/riak/rel/riak/bin/../etc, activating cuttlefish
config is OK
-config /Users/joe/dev/basho/riak/rel/riak/bin/../etc/generated/app.2013.08.29.11.56.27.config -args_file /Users/joe/dev/basho/riak/rel/riak/bin/../etc/generated/vm.2013.08.29.11.56.27.args
Exec: /Users/joe/dev/basho/riak/rel/riak/bin/../erts-5.9.3.1/bin/erlexec -boot /Users/joe/dev/basho/riak/rel/riak/bin/../releases/1.4.0/riak               -config /Users/joe/dev/basho/riak/rel/riak/bin/../etc/generated/app.2013.08.29.11.56.27.config -args_file /Users/joe/dev/basho/riak/rel/riak/bin/../etc/generated/vm.2013.08.29.11.56.27.args              -pa /Users/joe/dev/basho/riak/rel/riak/bin/../lib/basho-patches -- console
Root: /Users/joe/dev/basho/riak/rel/riak/bin/..
Erlang R15B03 (erts-5.9.3.1) [source] [64-bit] [smp:4:4] [async-threads:64] [kernel-poll:true]

Eshell V5.9.3.1  (abort with ^G)
(riak@127.0.0.1)1> q().
ok

As you can see, there are some egrep errors I'm going to need some help hiding, since those errors aren't actually important. I figure @jaredmorrow can school me on some sh in the process.

Also, some comments in-line where helpful.

[joedevivo]

nested if. If name's in vm.args, use it. If not, check conf file.

[jaredmorrow]

+1, please squash before merging.