fix: Invalid column of the element, positioned before the first line separator

[Egor18]

Hi! I've found that spoon gives incorrect column number for the element, positioned before the first line separator in file.

Consider the following file (TestSimpleClass.java):

public class TestSimpleClass {
    public int x;
    public int y;
    public int z;
}

If you try to get column from postion of this class, you will get -69, which is incorrect.
So, this PR is intended to fix that.

[Egor18]

It seems like Travis CI build failed with timeout. Could you please run it again?

[pvojtechovsky]

I cannot personally run CI again, but there is an easy way. To commit a minor change - e.g to add a dot at the end of some comment sentence and push it.

[pvojtechovsky]

I suggest to put there 'return position' too. It is probably the case when source contains only one line without EOL.

[monperrus]

@Egor18, ping?