GUI.OnScreensaverDeactivated does not follow JSON-RPC API definition

The announcement of `GUI.OnScreensaverDeactivated` does not follow the
defined API - it outputs `data` as a `boolean`, not `null`.  This
behaviour was introduced in ea9f2f01 to support a special case for CEC
devices, that must choose to act based on whether this notification was
triggered on the back of a shutdown.

As the rest of the API defines `data` to be of type `null` or `object`,
I've moved this boolean to a `shuttingDown` member on the data object,
rather than changing the API to be inconsistent for a special case.
Bump json-rpc schema version
Merge pull request #4661 from pdf/fix_OnScreensaverDeactivated_API

json-rpc: GUI.OnScreensaverDeactivated does not follow JSON-RPC API definition
NfoFile: do a range check before extracting a sub-string
NfoFile: simplify checking for multiple <episodedetails> elements
NfoFile: do a range check before calling GetDetails
json-rpc: add possibility to force using the default player through Player.Open
Merge pull request #5454 from Montellese/jsonrpc_player_open_default

json-rpc: add possibility to force using the default player through Player.Open
Rebrand: change visual reference to new app name
Merge pull request #5485 from Montellese/fix_nfo_crash_15472

Fix episode NFO scraping
Merge pull request #5486 from Voyager1/rebrand

Rebrand: change visual occurrences of XBMC to reflect new app name
Language and Settings: Rename normalizevolumes to maintainoriginalvolume
ActiveAE: Maintain original volume is the inverse of normalizelevels
Maintain original volume: Move it to expert settings and enable it by default
Merge pull request #5415 from fritsch/boost-volume

Audio: Rename normalize audio to Maintain original volume and invert meaning