Add pull request 4811 (SysInfo refactoring, startup log update).

Replace 04-XBianSysSum13.patch with 91-systeminfo-remove-battery-level.diff.
It just removes "Battery level" from SystemInfo window.
build-xbmc: fix JsonSchemaBuilder after xbmc/xbmc@0765a526f6993239d592a79ec28d81ce68318cf5.

Delete 91-jsonschemabuilder-fix-cross-compilation.diff as it's no longer needed.
Refresh popcornmix/newclock3 patch.