Add build:toggle-view command

[sryze]

This command allows you to show or hide the build view. The default shortcut is cmd-alt-b cmd-alt-v (Mac) or ctrl-alt-b ctrl-alt-v (others).

[sryze]

I guess the shortcut should be changed, currently it makes build:trigger wait for the second key press for a little while before building.

[noseglid]

I like this!

It's smart to use *-alt-v so it doesnt freeze *-alt-b for a second or so.

I've recently made some changes on how visibility is set (due to #62). Is this compatible with those changes??

[noseglid]

force flag has been added to attach as well in commit cc66db0 this must be passed here as well.

Also, I think this can be written neater by

this.isAttached() ? this.detach(true) : this.attach(true);

[sryze]

I guess that one looks better, yeah. Though I've mostly seen the ternary operator used when something is actually being returned (i.e. as part of an expression).

[noseglid]

I tested it, and it almost works. attach needs the force flag as well.
Have a look at my comments. If you agree, fix them - otherwise argue why you shouldn't :)

Thanks for the effort in implementing this!

[sryze]

Should I also rename this to toggle-window? I just noticed that it's called a window everywhere instead of a view (kind of confusing given the class name).

[noseglid]

Or build panel (the thing we show is internally called a panel in atom).

Also, other config variables refer to it as build-panel.

[sryze]

OK, done.

[noseglid]

Excellent. Great job! I will include it in the next version v0.31.0.