Fix build with gcc
clients/status_bar: Use timer_settime instead of setitimer
Use rule-specific variables
Add wayland-server dependency to protocol objects
Makefile: Drop quotes in directory names

If the packager wants directories which need to be quoted, they should
supply the quotes in the *DIR variables.
Fix installation of velox executable and protocol
Install status_bar client
Start status_bar on initialization
Ignore title change events when window is not managed
Some style fixes
Add previous_tags action
Run swc_finalize on error