Add missing forward declaration
Add proper (de)initialization to abstract shell surface
Remove unused forward declaration
Adjust initialization of ws_shell_surface
Adjust initialization of xdg_surface
Move methods for setting the position to the abstract surface
Fix recognicion of repeated events

Turns out the value is not `1` for repeated events, but `2`. This means
that:
 * my previous approach broke because I was comparing the value directly
 * instead of looking things up in an array, I can just look at the
   value and use _this_ as a base for recognicion of repeated events
Add missing reset of the hotkeys' state
Merge pull request #539 from neithernut/mod-compositor-consolidate_shell_surfaces

Mod compositor consolidate shell surfaces
Add shutdown configuration

Add configuration transactions for registering a shutdown
transaction on STRG-ALT-Q.
Merge pull request #537 from neithernut/fix-hotkeys-keypress_evaluation

Fix hotkey evaluation
Add registered shutdown transaction in user docu
Add autogobble package for removing initial indentation in listings
Change ws_object_hash() to return errno on failure
Add comment why ws_error_reply_get_code() doesn't do locking
Add comment why ws_error_reply_get_description() doesn't do locking
Add comment why ws_error_reply_get_cause() doesn't do locking
Add getref() in ws_event_get_name()
Add locking in ws_transaction_push_statement()
Add locking in deinit_transaction()