Delete and append instead of setline, to prevent bug when result line…

[iovar]

When the lines after combing are fewer than before combing, the extra lines remain in the buffer and mess up the file. e.g.

.format {
width: 100px;
height: 200px;

border: 2px solid blue;
}

will result to this:

.format {
width: 100px;
height: 200px;
border: 2px solid blue;
}
}

By deleting the lines and then appending, this doesn't happen and the result is correct.

[netcookies]

u may want to use "delete_" instead of "delete", prevent to cut the tempfile in clipboard