Smart selection manipulation commands

[NNBnh]

The following command is useless if there is only one cursor with no selection:

Key	Description	Command
s	Select all regex matches inside selections	select_regex
S	Split selection into subselections on regex matches	split_selection

We could make a "smart selection commands" that auto select the whole file when using these two commands if there is only one cursor with no selection, saving 2 keypress when user want to select all regex inside file (a very common operation):

• From Shift + 5 ; s = 3.
• To s = 1.

The downside:

• Inconsistent: because w, b, e ... create a selection, if user try to select all regex inside file right after those keypress, it will just select regex matches inside selection.