fix bug with numpy 1.7.1 and VigraArray.reshape

Reshaping a VigraArray raises an error because there's an undocumented keyword argument in numpy.reshape().
Merge pull request #143 from burgerdev/patch-1

fix bug with numpy 1.7.1 and VigraArray.reshape
added TinyVector functions and tests
added MetaPow
big refactoring of multi-dimensional iterators,
minor documentation fixes
added 2D slic superpixels
renamed acc::detail => acc::acc_detail (enables 'using namespace acc')
added CoupledArrays, fixed CoupledScanOrderIterator::restrictToSubarray()
simplified accumulator usage
refactored slic superpixels
added GridGraph
added missing 'template'
added operator<<(ostream, StridedScanOrderIterator)
removed 'auto' (compiler too old)
fixed redefinition of boost::tie
improved accumulator documentation and tests
cmake: improved VigraFindPackage
added GridGraph and tests
use dimension-independent labeling in slic