[web] Made titles unique.

Uniqueness of titles are required in the same menu section (benchmarks)

web/content/docs/benchmarks/hydro-component/elder.md

@@ -3,7 +3,7 @@ author = "Marc Walther"
 weight = 142
 project = "Parabolic/ComponentTransport/elder/"
 date = "2017-09-07T14:41:09+01:00"
-title = "Saturated Variable-Density Flow and Mass Transport"
+title = "Saturated Variable-Density Flow and Mass Transport (Elder)"
 
 [menu]
   [menu.benchmarks]

web/content/docs/benchmarks/hydro-component/goswami.md

@@ -3,7 +3,7 @@ author = "Marc Walther"
 weight = 142
 project = "Parabolic/ComponentTransport/goswami/"
 date = "2017-09-07T14:41:09+01:00"
-title = "Saturated Variable-Density Flow and Mass Transport"
+title = "Saturated Variable-Density Flow and Mass Transport (Goswami)"
 
 [menu]
   [menu.benchmarks]
@@ -39,4 +39,4 @@ A comparison of numerical and laboratory data is shown in the figure below. The
 
 Goswami, R.R., Clement, T.P., 2007. Laboratory-scale investigation of saltwater intrusion dynamics. Water Resour. Res. 43, 1–11. doi:10.1029/2006WR005151.
 
-Kolditz, O., Görke, U.-J., Shao, H., Wang, W., 2012. Thermo-Hydro-Mechanical-Chemical Processes in Porous Media: Benchmarks and Examples, Lecture notes in computational science and engineering. Springer. ISBN: 3642271766.
+Kolditz, O., Görke, U.-J., Shao, H., Wang, W., 2012. Thermo-Hydro-Mechanical-Chemical Processes in Porous Media: Benchmarks and Examples, Lecture notes in computational science and engineering. Springer. ISBN: 3642271766.
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