Blank lines not read

[Lesterpig]

Hi !
I've got a problem with blank lines parsing.
Assuming I want to send this message : "I am\na text.\n\nHello World!".
The server will encode it as :

data: I am\n
data: a text.\n
data: \n
data: Hello World!\n\n

But eventsource will parse it and give : "I am\na text.\nHello World!"
On Chrome, with the same server, I get the correct message.

Thank's !

[Lesterpig]

Just created a pull request for this.