LatticeTiling: whitespace changes
LatticeTilingTest: allow any metric or mismatch to be passed to MismatchTest()
testCFSv2_grids.sh: disable checking gridTypes 8 and 9

- Refs #1756
LatticeTiling: refactor tiling state structure

- LatticeTiling structure now split into several structures:
  * LatticeTilingSpace encodes the parameter-space bounds
  * LatticeTiling remains the state structure, which is built from LatticeTilingSpace;
    all bound information is now computed once and stored in the bound trie, and so
    the parameter-space bound functions are not stored nor used by LatticeTiling
  * LatticeTilingIterator iterates over the lattice tiling stored in LatticeTiling
- Various other API and internal change
- Refs #1756
LatticeTiling: automatic bound padding and polling of missed points

- LT_FindBoundExtrema() finds extreme values of the physical bounds,
  by sampling the bounds around the current point, removing the need
  to manually specify padding in SuperSkyMetrics bound functions
- LT_PollNearestPoint() finds the nearest point within the parameter-
  space bounds of the lattice tiling, in case the point found by
  LT_FindNearestPoint() is outside the parameter-space bounds
- Refs #1756
LatticeTilingTest: fix format specifiers