Add support for completion requests from empty character

Given:

<foo>
    <bar>
     // press ctrl-space here
</foo>

There’s no completion until I press <. While I understand autocompletion is triggered on <, explicit completion requests (ctrl+space), should also return results from anywhere in the document. In this case, it should return </bar>.

In Eclipse, when explicitely requesting completion from an empty space, you get : 1 - proposition to close the last opened tag 2 - list of all possible tags (i.e existing siblings)

1/ is really important. 2/ we can probably live without for a bit.

[angelozerr]

@fbricon I have improved a lot the close tag (works with empty character, indent apply of completion, provide several close tag to close. See the following demo:

Please closet this issue of it’s OK for you.

[angelozerr]

Glad it pleases you @fbricon !