Relative and absolute paths for a relocatable pkgconf file #217

Job	Run time
windows (Win32, standard)	1m 0s
ubuntu (g++, standard)	55s
windows (Win32, PUGIXML_WCHAR_MODE)	1m 29s
ubuntu (g++, PUGIXML_WCHAR_MODE)	54s
windows (Win32, PUGIXML_COMPACT)	1m 32s
ubuntu (g++, PUGIXML_COMPACT)	57s
windows (Win32, PUGIXML_NO_EXCEPTIONS)	1m 29s
ubuntu (g++, PUGIXML_NO_EXCEPTIONS)	53s
windows (x64, standard)	1m 23s
ubuntu (clang++, standard)	39s
windows (x64, PUGIXML_WCHAR_MODE)	1m 6s
ubuntu (clang++, PUGIXML_WCHAR_MODE)	41s
windows (x64, PUGIXML_COMPACT)	1m 38s
ubuntu (clang++, PUGIXML_COMPACT)	51s
windows (x64, PUGIXML_NO_EXCEPTIONS)	1m 28s
ubuntu (clang++, PUGIXML_NO_EXCEPTIONS)	38s
macos (clang++, standard)	1m 30s
macos (clang++, PUGIXML_WCHAR_MODE)	2m 39s
macos (clang++, PUGIXML_COMPACT)	1m 17s
macos (clang++, PUGIXML_NO_EXCEPTIONS)	2m 14s
	25m 13s

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