Add leftrelease override to call the activatenode method on single click

[Matrix86]

Requirements (please check off with 'x')

• I have read the Contributing Guidelines
• I have read or at least glanced at the FAQ
• I have read or at least glanced at the Wiki

What does this Pull Request (PR) do?

When you open a directory on the nerdtree plugin the directory icon doesn't open. This PR permits to call the activatenode method on the single click, when the user try to open a directory.

How should this be manually tested?

Try to open a directory on nerdtree plugin. The icon will change with on the single click event.

Any background context you can provide?

I don't think you need other info.

What are the relevant tickets (if any)?

Screenshots (if appropriate or helpful)

[ryanoasis]

I realize that with this double click will obviously not be the way to open the directories but I think this might be preferable. Do you have any info on that?

So far this looks good to me...

[der-flo]

In my opinion this change collides with let g:NERDTreeMouseMode = 1, which is the default.

https://github.com/scrooloose/nerdtree/blob/master/doc/NERDTree.txt says:

If set to 1 then a double click on a node is required to open it.

Nope, with this commit and let g:DevIconsEnableFoldersOpenClose = 1 single clicks instead of double clicks open dir nodes.

[Matrix86]

In my opinion this change collides with let g:NERDTreeMouseMode = 1, which is the default.

https://github.com/scrooloose/nerdtree/blob/master/doc/NERDTree.txt says:

If set to 1 then a double click on a node is required to open it.

Nope, with this commit and let g:DevIconsEnableFoldersOpenClose = 1 single clicks instead of double clicks open dir nodes.

You're right! My bad...I hope the new PR can fix the problem.

[ryanoasis]

Thanks. I just felt I wanted to get your work in but I'll review your other PR when able