+ The "main" workspace is no longer treated especially, and can be
renamed or deleted. Fixes issue mentioned in #200.
+ In the disastrous event that there are no workspaces left, a main one
is generated and switched to. Under no circumstances should the use be
left in the nil perspective!
+ Fix the :tabr[ename] ex command throwing argument errors.
+ Refactored most workspace functions.
+ New command: +workspace/close-workspace-or-frame, which is bound to
C-S-w in my private module.
de35ac873a