Added 1m-specific APIs for bp, pb gemm algorithms.

Details:
- Defined bli_gemmbp_cntl_create(), bli_gemmpb_cntl_create(), with the
  body of bli_gemm_cntl_create() replaced with a call to the former.
- Defined bli_cntl_free_w_thrinfo(), bli_cntl_free_wo_thrinfo(). Now,
  bli_cntl_free() can check if the thread parameter is NULL, and if so,
  call the latter, and otherwise call the former.
- Defined bli_gemm1mbp_cntx_init(), bli_gemm1mpb_cntx_init(), both in
  terms of bli_gemm1mxx_cntx_init(), which behaves the same as
  bli_gemm1m_cntx_init() did before, except that an extra bool parameter
  (is_pb) is used to support both bp and pb algorithms (including to
  support the anti-preference field described below).
- Added support for "anti-preference" in context. The anti_pref field,
  when true, will toggle the boolean return value of routines such as
  bli_cntx_l3_ukr_eff_prefers_storage_of(), which has the net effect of
  causing BLIS to transpose the operation to achieve disagreement (rather
  than agreement) between the storage of C and the micro-kernel output
  preference. This disagreement is needed for panel-block implementations,
  since they induce a transposition of the suboperation immediately before
  the macro-kernel is called, which changes the apparent storage of C. For
  now, anti-preference is used only with the pb algorithm for 1m (and not
  with any other non-1m implementation).
- Defined new functions,
    bli_cntx_l3_ukr_eff_prefers_storage_of()
    bli_cntx_l3_ukr_eff_dislikes_storage_of()
    bli_cntx_l3_nat_ukr_eff_prefers_storage_of()
    bli_cntx_l3_nat_ukr_eff_dislikes_storage_of()
  which are identical to their non-"eff" (effectively) counterparts except
  that they take the anti-preference field of the context into account.
- Explicitly initialize the anti-pref field to FALSE in
  bli_gks_cntx_set_l3_nat_ukr_prefs().
- Added bli_gemm_ker_var1.c, which implements a panel-block macro-kernel
  in terms of the existing block-panel macro-kernel _ker_var2(). This
  technique requires inducing transposes on all operands and swapping
  the A and B.
- Changed bli_obj_induce_trans() macro so that pack-related fields are
  also changed to reflect the induced transposition.
- Added a temporary hack to bli_l3_3m4m1m_oapi.c that allows us to easily
  specify the 1m algorithm (block-panel or panel-block).
- Renamed the following cntx_t-related macros:
    bli_cntx_get_pack_schema_a() -> bli_cntx_get_pack_schema_a_block()
    bli_cntx_get_pack_schema_b() -> bli_cntx_get_pack_schema_b_panel()
    bli_cntx_get_pack_schema_c() -> bli_cntx_get_pack_schema_c_panel()
  and updated all instantiations. Also updated the field names in the
  cntx_t struct.
- Comment updates.

frame/include/bli_obj_macro_defs.h

@@ -877,6 +877,12 @@ bli_obj_width_stored( obj )
 	(obj).n_panel = n0; \
 }
 
+#define bli_obj_set_panel_dims( m0, n0, obj ) \
+{ \
+	bli_obj_set_panel_length( m0, obj ); \
+	bli_obj_set_panel_width( n0, obj ); \
+}
+
 #define bli_obj_set_panel_dim( panel_dim, obj ) \
 { \
 	(obj).pd = panel_dim; \
@@ -985,6 +991,7 @@ bli_obj_width_stored( obj )
 #define bli_obj_induce_trans( obj ) \
 { \
 	{ \
+		/* Induce transposition among basic fields. */ \
 		dim_t  m_        = bli_obj_length( obj ); \
 		dim_t  n_        = bli_obj_width( obj ); \
 		inc_t  rs_       = bli_obj_row_stride( obj ); \
@@ -1000,6 +1007,15 @@ bli_obj_width_stored( obj )
 \
 		if ( bli_obj_is_upper_or_lower( obj ) ) \
 			bli_obj_toggle_uplo( obj ); \
+\
+		/* Induce transposition among packed fields. */ \
+		dim_t  m_padded_ = bli_obj_padded_length( obj ); \
+		dim_t  n_padded_ = bli_obj_padded_width( obj ); \
+		dim_t  m_panel_  = bli_obj_panel_length( obj ); \
+		dim_t  n_panel_  = bli_obj_panel_width( obj ); \
+\
+		bli_obj_set_padded_dims( n_padded_, m_padded_, obj ); \
+		bli_obj_set_panel_dims( n_panel_, m_panel_, obj ); \
 \
 		/* Note that this macro DOES NOT touch the transposition bit! If
 		   the calling code is using this macro to handle an object whose

frame/include/bli_type_defs.h

@@ -975,9 +975,11 @@ typedef struct cntx_s
 
 	opid_t    family;
 	ind_t     method;
-	pack_t    schema_a;
-	pack_t    schema_b;
-	pack_t    schema_c;
+	pack_t    schema_a_block;
+	pack_t    schema_b_panel;
+	pack_t    schema_c_panel;
+
+	bool_t    anti_pref;
 
 	dim_t     thrloop[ BLIS_NUM_LOOPS ];