Update ini.js

Added the possibility to decode and encode the comments so they can be carried over during a modification.
I found this feature was lacking for us.

This basically adds an option on the encode() method {comments:true} and adds an option object on the decode() for the same option.
By default everything behaves as usual, but adding comments:true option, then option can be decoded into the object and then encode back to the ini file.
While an parsed object, the comments are stored in a property named like so : /\$com\$[0-9]+/
not ideal, but working.