GSL 1.15 Test Release

[Brian Gladman]

I have just had a quick look at this on Microsoft Visual Studio 2010 and I 
notice failures when compiling in C as a result of the use of C99's 'out of 
order' declarations (which VC++ doesn't support for C code).

I can deal with these but, before doing so, I wanted to check that this C99 
feature is now acceptable in GSL code and that the use of this feaature is 
not an oversight.

   with my regards,

        Brian Gladman