reftest: untie lock test from OPAMEDITOR hack, and fix lock VCS remote detection #4142

Job	Run time
Analyse	4s
Cygwin	3s
Hygiene	41s
Build-Linux (4.08.1)	2m 21s
Build-macOS (4.14.2)	2m 55s
Build-Linux (4.09.1)	2m 27s
Test-macOS (4.14.2)	15m 10s
Build-macOS (5.3.0)	2m 50s
Build-Linux (4.10.2)	2m 28s
Test-macOS (5.3.0)	13m 13s
Build-Linux (4.11.2)	2m 30s
Build-Linux (4.12.1)	2m 38s
Build-Linux (4.13.1)	2m 29s
Build-Linux (5.0.0)	2m 29s
Build-Linux (5.1.1)	3m 27s
Build-Linux (5.2.1)	2m 16s
Build-Linux (4.14.2)	2m 25s
Build-Linux (5.3.0)	2m 28s
Build-Windows (x86_64-pc-cygwin, x86_64-pc-cygwin, 4.14.2)	35m 0s
Build-Windows (i686-w64-mingw32, x86_64-pc-cygwin, 4.14.2)	38m 30s
Build-Windows (x86_64-w64-mingw32, x86_64-pc-cygwin, 4.14.2)	41m 29s
Build-Windows (i686-pc-windows, x86_64-pc-cygwin, 4.14.2)	40m 55s
Build-Windows (x86_64-pc-windows, x86_64-pc-cygwin, 4.14.2)	42m 37s
Build-Windows (x86_64-w64-mingw32, x86_64-pc-cygwin, 5.3.0)	40m 53s
Build-Windows (x86_64-pc-windows, x86_64-pc-cygwin, 5.3.0)	39m 52s
Solvers-macOS (z3, 4.14.2)	1m 11s
Upgrade-macOS (4.14.2)	1m 57s
Solvers-macOS (z3, 5.3.0)	1m 32s
Upgrade-macOS (5.3.0)	1m 45s
Solvers-macOS (0install, 4.14.2)	1m 19s
Solvers-macOS (0install, 5.3.0)	1m 25s
Cold-Linux	5m 11s
Test-Linux (4.14.2)	8m 15s
Solvers-Linux (z3, 4.14.2)	56s
Doc-Linux (4.14.2)	1m 17s
Test-Linux (5.3.0)	7m 33s
Solvers-Linux (z3, 5.3.0)	56s
Doc-Linux (5.3.0)	1m 22s
Upgrade-Linux (4.14.2)	1m 20s
Solvers-Linux (0install, 4.14.2)	1m 39s
Upgrade-Linux (5.3.0)	1m 33s
Solvers-Linux (0install, 5.3.0)	1m 29s
	6h 22m 50s

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