Version 20140528:
* Improvement: 'windows' key is now the default META key

* Bugfix: seldomly triggered crash in memory pool
* Bugfix: save the session atomically
* Bugfix: various fixes to contributed scripts, notably more lua5.2 support

* Improvement: various code cleanups (thanks to Campbell Barton)
* Improvement: various build/packaging improvements (thanks to Dima Kogan)

* Feature: Workspace indicator (thanks to Dima Kogan)
* Feature: Delayed population of the focuslist (thanks to Dima Kogan)

* Improvement: improved kludges/focus behavior (IntelliJ IDEA, xeyes)
* Improvement: expose 'warp_pointer' to lua
* Improvement: lock using i3lock when available
