Merge tag '140714' into 000000-dev

Releasing Quick Cache v140725
Fix spelling error on Auto-Cache Engine options panel (props @Greduan)
Converting <div> to <a>. Working toward a resolution in websharks/quick-cache#260
<a> display:block; see websharks/quick-cache#260
Update JS handler; see websharks/quick-cache#260
Final tweaks and testing; see websharks/quick-cache#260
Improve portability of `advanced-cache.php` with respect to `%%QUICK_CACHE_PLUGIN_FILE%%`; see websharks/quick-cache#258
Improve placeholder styles in menu pages; see websharks/quick-cache#235
Adding Uninstall Routine; see websharks/quick-cache#261
Plugin Deletion Safeguards; see websharks/quick-cache#261
Merge remote-tracking branch 'origin/feature/258' into feature/258
Merge branch 'feature/258' into 000000-dev
Merge remote-tracking branch 'origin/feature/260' into feature/260

Conflicts:
	quick-cache/client-s/css/menu-pages.min.css - Fixed manually
Merge branch 'feature/260' into 000000-dev
Merge remote-tracking branch 'origin/feature/261' into feature/261

Conflicts:
	quick-cache/includes/menu-pages.php - Fixed manually
Merge branch 'feature/261' into 000000-dev
Symlink 404 cache files atomically to avoid potential race condition.

See websharks/quick-cache#242
Fix bug and improve code in 404 symlink creation.

See websharks/quick-cache#242
Merge branch 'feature/242' into 000000-dev
Auto-purge feeds (just getting started); see websharks/quick-cache#182