print doesn't output anything until println has been written after it

### Summary

When typing:
`print("test");`
then nothing shows up in the live editors console.

To get the print command to output anything, add a println command after the print command.
for example:
`println("test2");`
### Expected Behavior

When writing a print command, then it should output to the live editors console once, without adding a new line.
### Actual behavior

Nothing happens.

There's another strange behavior:
When the print command doesn't output anything, then it seems to be stored somewhere, because if the `print("test");` is written once and then commented and uncommented a couple of times with the hotkey: (ctrl + /).
Then if `println("test2");` is written below the print command, now the print command gets written to the console several times, the steps are explained below.
### Steps to Reproduce
1. type: `print("test");`
nothing happens
2. type: `println("test2");`

The live editors console now opens and shows the following:

```
testtesttest
test2
```

For some reason the print command is written 3 times.
If the println command is commented and uncommented once, then the print command is written twice:

```
testtest
test2
```

To see that the print commands output is stored somewhere until the println command is called.

Comment out the second line:

```
print("test");
// println("test2");
```

Now comment and uncomment the first line 5 times (hotkey: ctrl + /):

```
// print("test");
// println("test2");
```

Finally if the first line is commented, then uncomment it, now uncomment the second line,
and the console shows:

```
testtesttesttesttesttesttest
test2
```
### Environment

OS: Windows 7 Home Premium 64 bit
Browser: Google Chrome Version 49.0.2623.112 m

Start by reproducing the issue in the live editor console with print("test"); and println("test2");, including repeated comment and uncomment actions. Trace how the editor executes changed code and buffers console output; done means print appears once without println and comment toggling does not duplicate it.

Written by the indexing model from the issue text.