restore the hydrostatic equilibration test from opm-core

This involved quite a bit of kicking and screaming. The result
certainly is not pretty, but it works.

tests/equil_base.DATA

@@ -0,0 +1,115 @@
+RUNSPEC
+
+WATER
+GAS
+OIL
+
+METRIC
+
+DIMENS
+   10 1 10 /
+
+GRID
+
+DX 
+   	100*1 /
+DY
+	100*1 /
+DZ
+	100*1 /
+
+TOPS
+	10*0. /
+
+PORO
+   	100*0.3 /
+
+PERMX
+	100*500 /
+
+PROPS
+
+PVTW
+    	4017.55 1.038 3.22E-6 0.318 0.0 /
+
+ROCK
+	14.7 3E-6 /
+
+SWOF
+0.12	0    		 	1	0
+0.18	4.64876033057851E-008	1	0
+0.24	0.000000186		0.997	0
+0.3	4.18388429752066E-007	0.98	0
+0.36	7.43801652892562E-007	0.7	0
+0.42	1.16219008264463E-006	0.35	0
+0.48	1.67355371900826E-006	0.2	0
+0.54	2.27789256198347E-006	0.09	0
+0.6	2.97520661157025E-006	0.021	0
+0.66	3.7654958677686E-006	0.01	0
+0.72	4.64876033057851E-006	0.001	0
+0.78	0.000005625		0.0001	0
+0.84	6.69421487603306E-006	0	0
+0.91	8.05914256198347E-006	0	0
+1	0.00001			0	0 /
+
+
+SGOF
+0	0	1	0
+0.001	0	1	0
+0.02	0	0.997	0
+0.05	0.005	0.980	0
+0.12	0.025	0.700	0
+0.2	0.075	0.350	0
+0.25	0.125	0.200	0
+0.3	0.190	0.090	0
+0.4	0.410	0.021	0
+0.45	0.60	0.010	0
+0.5	0.72	0.001	0
+0.6	0.87	0.0001	0
+0.7	0.94	0.000	0
+0.85	0.98	0.000	0 
+0.88	0.984	0.000	0 /
+
+DENSITY
+      	53.66 64.49 0.0533 /
+
+PVDG
+14.700	166.666	0.008000
+264.70	12.0930	0.009600
+514.70	6.27400	0.011200
+1014.7	3.19700	0.014000
+2014.7	1.61400	0.018900
+2514.7	1.29400	0.020800
+3014.7	1.08000	0.022800
+4014.7	0.81100	0.026800
+5014.7	0.64900	0.030900
+9014.7	0.38600	0.047000 /
+
+PVTO
+0.0010	14.7	1.0620	1.0400 /
+0.0905	264.7	1.1500	0.9750 /
+0.1800	514.7	1.2070	0.9100 /
+0.3710	1014.7	1.2950	0.8300 /
+0.6360	2014.7	1.4350	0.6950 /
+0.7750	2514.7	1.5000	0.6410 /
+0.9300	3014.7	1.5650	0.5940 /
+1.2700	4014.7	1.6950	0.5100 
+	9014.7	1.5790	0.7400 /
+1.6180	5014.7	1.8270	0.4490 
+	9014.7	1.7370	0.6310 /	
+/
+
+SOLUTION
+
+SWAT
+ 100*0.0 /
+
+SGAS
+ 100*0.0 /
+
+PRESSURE
+ 100*300.0 /
+
+SUMMARY
+
+SCHEDULE