No desktop notification for empty headless servers

Also added fixes as suggested by JSHint (consistent indentation,
multi-line statements have the operator at the end of the line,
favouring strict comparisons).
Improved DOM handling of auto-refresher

Table and usage list are now identified by unique IDs, making
future modifications safer.
Script properly updates play date, not build date

Also fixed comments referring to build date.
Bug fixes and updates for desktop notifications.
Merge branch 'master' of https://github.com/MegaGlest/megaglest-source