Need separating source and build directory

[ssenesi]

XIOS make system is fine.

However, when testing various configurations of architecture files, and hence building various versions of libraries and binaries, it would be much useful if the 'obj' and 'bin' directory were suffixed by the 'arch' value. This in order to avoid multiplying directories with the whole distro (and hence mutliplying the ARCH directories, which inevitably leads to mixing arch files versions ...)

[oabramkina]

Done (r1498).

[ssenesi]

Thanks