Fixes/Hints for "Installing on Mac OS X > MacPorts" section

[pulkitsinghal]

The comments pertain to the following section:
http://guide.couchdb.org/draft/mac.html#macports

1. sudo port install couchdb will result in the following output at the very end:
   couchdb requires erlang to be installed with ssl support (+ssl)
   Just know that everything is fine, no mistake has been made, no need to panic.

2. Instead of using only couchdb, it is more appropriate to use sudo couchdb.
   Otherwise errors like the following will crash the server at startup:

=CRASH REPORT= exception exit: {file_permission_error, "/opt/local/var/log/couchdb/couch.log"}