0.5.4-Alpha3

changes:

- converted "API whitelist" to "protected API features" (automatic settings migration)
- notification details are not stored by default

new features:

- added save/load directly to/from file option
- added protection for DOMRect (getClientRects)
- added setting to control if notification details should be stored

fixes:

- window and audio API were always blocked when using any of the "block ..." modes
- canvas content was not stored to be displayed when wanted

known issues:

- if a data URL is blocked the page action button does not appear