Improve UI for permissions editing

We need to make it a little more self-consistent. I'm similarly confused by the fact that you do some things on the view screen and some on the edit screen.

Inspired by the following forum post:

"Regarding the new UI for space permissions in 1.2, I find it a bit
unintuitive and inconsistant.
And though the new one is visually nice, I didint think there was a problem
with original one such that it required changing - it was nice and simple
and intuitive .

1) For the permission table, why is Browse not a column heading?
2) Why is some of the permission editing done on the first "View Space
Permissions" page and some done on the "edit permissions" page?

I think there can be a few improvements:

1) View Space Permissions should be just that: viewing.
2) "Browse" should be a column heading for both View and Edit Permissions.
3) Edit Permissions should have the select lists (that are currently on
View)
4) The buttons for the select lists should be called "Add" (rather than
"ok")"