[PYTHON][TESTS][DOC] Various improvement of the API and code quality:

* Simplified `triton.kernel` API to achieve lower latency:
  > .data_ptr() must now be passed as kernel argument. No more implicit
conversion from torch.tensor
  > compilation options are now constant attributes, i.e., opt.d('VAR')
becomes opt.VAR
  > torch.device must now be passed explicitly to triton.kernel (no
longer inferred from torch.tensor arguments)
* C++ tests moved to `python/tests/`
* C++ tutorial created in `tutorials/`
* Python tutorial created in python/tutorials/
* Version changed to 1.0alpha
* No longer copying C++ headers into the Python package
* added python/triton/ops/ package for pre-written Triton ops

lib/codegen/analysis/layout.cc

@@ -168,7 +168,6 @@ mma_layout::mma_layout(size_t num_warps,
     bool is_b_vec4 =  is_b_row && (layout_b->get_shape()[ord_b[0]] <= 16);
     int pack_size_0 = (is_a_row ||  is_a_vec4) ? 1 : 2;
     int pack_size_1 = (is_b_row && !is_b_vec4) ? 2 : 1;
-    pack_size_0 = pack_size_1 = 1;
     rep_ = {2*pack_size_0, 2*pack_size_1, 1};
     spw_ = {fpw_[0]*4*rep_[0], fpw_[1]*4*rep_[1], 1};
   }