fix bug in Esurf regex that caused regr tests to fail
fix bug in Esurf regex that caused regr tests to fail

ARGH.

Single surface problems have an ending like this:
```
--------------------------------
Totals:
Esolv = 0.000000 kcal/mol
Esurf = 203445994.961314 kcal/mol
Ecoul = 0.000000 kcal/mol
```

And that is the kind of thing the regex patterns search for.
Specifically, they search for

```
'Esurf = (\-*\d*\.\d*)\ kcal\/mol'
```

which worked great for single surface problems.  The problem is that
multisurface problems, which I had never run, end like this:

```
Calculate Esurf
Calculating surface energy around region 1, stored in E_surf[0]
Calculating surface energy around region 2, stored in E_surf[1]
Region 1: Esurf = 101722997.492341 kcal/mol = 425609021.507957 kJ/mol
Region 2: Esurf = 101722997.468972 kcal/mol = 425609021.410180 kJ/mol
Time Esurf: 0.012774s

Calculate Ecoul
Time Ecoul: 0.000002s

--------------------------------
Totals:
Esolv = 0.000000 kcal/mol
Esurf = 203445994.961314 kcal/mol
Ecoul = 0.000000 kcal/mol
```

See the problem?  The regex will match the first instance of `Esurf =
numbers` and return that.

This fixes the problem by making the regex more strict and ignoring any
matches of `Esurf =` that are prefixed by `: `.

That took a long time to find.  Need tests for my regexes...


Former-commit-id: 4529cc3d8f1fc1e1e4ffe3d13e0cbc7d76c04df0
barbagroup/pygbe,barbagroup/pygbe,barbagroup/pygbe