Add setijm, getijm operations.

Details:
- Added bli_setgetijm.c, which defines bli_setijm(), bli_getijm(), and
  related functions that can be used to read and write individual
  elements of an obj_t.
- Defined a new function, bli_obj_create_conf_to(), in bli_obj.c that will
  create a new object with dimensions conformal to an existing object.
  Transposition and conjugation states on the existing object are ignored,
  as are structure and uplo fields.
- Defined a new function, bli_datatype_string(), in bli_obj.c that returns
  a char* to a string representation of the name of each num_t datatype.
  For example, BLIS_DOUBLE is "double" and BLIS_DCOMPLEX is "dcomplex".
  BLIS_INT is included (as "int"), but BLIS_CONSTANT is not, and thus is
  not a valid input argument to bli_datatype_string().
- Added calls to bli_init_once() to various functions in bli_obj.c, the
  most important of which was bli_obj_create_without_buffer().
- Removed unintended/extra newline from the end of printv output.
- Whitespace changes to
  - frame/base/bli_machval.c
  - frame/base/bli_machval.h
  - frame/0/copysc/bli_copysc.c
- Trivial changes to README.md and common.mk.

frame/include/blis.h

@@ -125,6 +125,7 @@ extern "C" {
 #include "bli_arch.h"
 #include "bli_cpuid.h"
 #include "bli_string.h"
+#include "bli_setgetij.h"
 
 
 // -- Level-0 operations --