Remove Summernote-branded footers

[phndiaye]

In Summernote editor's help, there is Summernote 0.8.2 · Project · Issues link.

We should delete it, except is just a p tag with no special class. So wether

• we just display: none the p if we are sure to not using any p in the modal footer.
• or we fork summernote, and just remove it.

As far as i am concerned, i think Solution 1 is a good one as i think we should only have Actions in the modal footer, and if we need explanatory text, an inline block like a span is more suitable anyway.