add support for xcode 11

[tmm1]

Description

the output of xcodebuild -showsdks after upgrading to xcode 11 is:

$ xcodebuild -showsdks
iOS SDKs:
	iOS 13.0                      	-sdk iphoneos13.0

iOS Simulator SDKs:
	Simulator - iOS 13.0          	-sdk iphonesimulator13.0

macOS SDKs:
	DriverKit 19.0                	-sdk driverkit.macosx19.0
	macOS 10.15                   	-sdk macosx10.15

tvOS SDKs:
	tvOS 13.0                     	-sdk appletvos13.0

tvOS Simulator SDKs:
	Simulator - tvOS 13.0         	-sdk appletvsimulator13.0

watchOS SDKs:
	watchOS 6.0                   	-sdk watchos6.0

watchOS Simulator SDKs:
	Simulator - watchOS 6.0       	-sdk watchsimulator6.0

[fuzzard]

can i suggest possibly changing found_sdk search to the following.

found_sdk_version=[`$use_xcodebuild -showsdks | grep macosx | sort | tail -n 1 | awk '{ print $2}'`]

Also, may be worthwile updating the ios/tvos while your in their. Again, up to you really.
Just need to add a 13.*);; after the following two lines

xbmc/tools/depends/configure.ac

Line 387 in a81e130

12.*);;

xbmc/tools/depends/configure.ac

Line 397 in a81e130

12.*);;

[fuzzard]

Looks good now, cheers

[ksooo]

jenkins build this please

[Rechi]

@ksooo please always set the milestone before or right after merging a PR.

[ksooo]

Ooops.