GDF mesh file reader limitation

[mancellin]

According to WAMIT manual, the mesh file format can be either

 header
ULEN GRAV
ISX ISY
NPAN
X1(1) Y1(1) Z1(1) X2(1) Y2(1) Z2(1) X3(1) Y3(1) Z3(1) X4(1) Y4(1) Z4(1)
X1(2) Y1(2) Z1(2) X2(2) Y2(2) Z2(2) X3(2) Y3(2) Z3(2) X4(2) Y4(2) Z4(2)
.
.
.
.  .  . . . . .  .  . . . . X4(NPAN) Y4(NPAN) Z4(NPAN) 

or

 header
ULEN GRAV
ISX ISY
NPAN
X1(1) Y1(1) Z1(1)
X2(1) Y2(1) Z2(1)
X3(1) Y3(1) Z3(1)
X4(1) Y4(1) Z4(1)
X1(2) Y1(2) Z1(2)
X2(2) Y2(2) Z2(2)
X3(2) Y3(2) Z3(2)
X4(2) Y4(2) Z4(2)
.
.
.
.
X4(NPAN) Y4(NPAN) Z4(NPAN) 

But only the latter is supported by Capytaine (and meshmagick I guess).

Actually, the documentation implies that the newline can be placed anywhere as long as there is one after the Z4(.), but I'm not considering supporting all cases.