Change the names of parser result structs

Change the name of structs CommandResult and ConfigResult to
CommandResultIR and ConfigResultIR to show they are an intermediate
representation used during parsing.
Fix test 517

Test 517 was sometimes failing because the command to reset the test
generates a focus event which was not being properly ignored.

Now the correct event should always be tested.
Bugfix: double X render on manage

When a con is being managed, tree_render should only be called once to
push the changes to the rendering server to prevent wasting resources.
Feature: Workspace assignment by number

Workspace assignments with bare numbers assign all workspaces with that
number to the specified output.

Workspace assignment by number is overridden by workspace assignment by
name.