Re-implemented micro-panel alignment.

Details:
- This commit re-implements a feature that was removed in commit
  c2b2ab62. It was removed because, at the time, I wasn't sure how the
  micro-panel alignment feature would interact with the 4m method (when
  applied at the micro-kernrel level), and so it seemed safer to disable
  the feature entirely rather than allow possible breakage. This commit
  revisits the issue and safely re-implements the feature in a way that
  is compatible with 4m, 3m, 4mh, and 3mh (and native execution).
- Modified the static memory pool to account for micro-panel alignment
  space.
- Modified packm_init and blocked variants to align whole micro-panels
  by a datatype-specific alignment value that may be set by the
  configuration. (If it is not set by the configuration, it will default
  to BLIS_SIZEOF_?.)
- Modified macro-kernels so that:
  - storage stride is handled properly given the new micro-panel
    alignment behavior;
  - indexing through 3m/4m/rih-type sub-panels, as is done by trmm and
    trsm, is more robust (e.g. will work if the applicable packing
    register blocksize is odd);
  - imaginary strides are computed and stored within auxinfo_t structs,
    which allows the virtual micro-kernels to more easily determine how
    to index into the micro-panel operands.
- Modified virtual 3m and 4m micro-kernels to use the imaginary strides
  within the auxinfo_t structs instead of panel strides.
- Deprecated the panel stride fields from the auxinfo_t structs.
- Updated test suite to print out the micro-panel alignment values.