Finalized thread-safety in convolutions for multithreading operations.
Fixed obsolete autoconf macros in configure.ac
Added support for the INTEL MKL library in place of ATLAS and FFTW (configure --enable-mkl option).
Updated LevMar library to V2.6.
Updated WCS library: added support for TPV ctypes and MJDSTART header keyword.
Updated FITS library to the latest version, removing potential conflicts with the CFITSIO library.
Fixed obsolete behaviour with 8 bit images (would suppose 8 bit integers are signed by default).