Incorrect in-place definition of static members in OffsetCurveBuilder

[mateusz@…]

In file geos/source/headers/geos/opBuffer.h, 
static data members are incorrectly defined in-place for class OffsetCurveBuilder:

static const double PI_OVER_2 = 1.570796326794895;
static const double MAX_CLOSING_SEG_LEN = 3.0;

ISO C++ forbids in-place initialization of member
constant of non-integral type (const double).
Only static const members of integral types can be initialized in-place in class definition.

(according to chapter 9.4.2, point 2 of 
"Standard for Programming Language C++")

GCC reports it only when used with -pedantic switch. VC++ 8.0 reports it as error by defailt.

Fix applied in attached patch

[mateusz@…]

Patch proposal created using cvs diff -Nua