add a flag for using old routing #319

Job	Run time
Apache2 tests on Linux	2m 33s
C++ tests on Linux	2m 22s
Apache2 tests on macOS	3m 6s
C++ tests on macOS	6m 0s
Nginx tests on Linux	3m 25s
Nginx tests on macOS	4m 5s
Homebrew packaging tests	8m 7s
Nginx dynamic module tests on Linux	1m 24s
Nginx dynamic module tests on macOS	1m 6s
Node.js tests on Linux	16s
Node.js tests on macOS	26s
Ruby tests on Linux	1m 29s
Ruby tests on macOS	1m 5s
Source packaging tests	33s
Passenger Standalone tests on Linux	3m 36s
Passenger Standalone tests on macOS	5m 6s
	44m 39s

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