Added parser error for 'random text'.

Previously random text in the input deck which was not formatted as a
valid keyword header was simply ignored; i.e. this

   DIMENS
     10 10 10 /

   Mohaha random gibbersih - not according to any Spec.

   GRID

Would suprisingly parse just fine. This will now be handled according
to the ParseMode::randomText setting. Observe that as a side effect of
this it turned out that many of the test datasets had additional
terminating slashes which were now detected as 'ranomdText'.

testdata/integration_tests/GRID/TOPS.DATA

@@ -63,7 +63,7 @@ PERMZ
 
 PORO
     162*0.3 /
-/
+
 
 
 PROPS    ===============================================================
@@ -429,7 +429,6 @@ WCONPROD
   /
 
 TSTEP                                            
- 4*500.0
-/
+ 4*500.0 /
 --
 END

testdata/integration_tests/POLYMER/plydhflf.data

@@ -7,4 +7,4 @@ PLYDHFLF
    0.0    365.0
    50.0   240.0  
    150.0  200.0 /
-/
+

testdata/integration_tests/POLYMER/plyvisc.data

@@ -6,4 +6,3 @@ TABDIMS
 PLYVISC
    0.0    1.0
    1.25   30.0  /
-/

testdata/integration_tests/SCHEDULE/wells_group.data

@@ -36,7 +36,7 @@ WELSPECS
 
 TSTEP
   14.0 /
-/
+
 
 WELSPECS
     'INJ2' 'G1'    1  1    8335 'GAS'  /
@@ -63,7 +63,7 @@ WCONPROD
 
 TSTEP
   3 /
-/
+
 
 
 END