add assertion method `assert_nothing_raised'

set bit field for mrb_bool

set bool macro

Reduce mrb_open calls in mrbgem test.

Add comments at end of include guard

Add comments to notify files are auto generated.

Use mrb_str_new_cstr() instead of mrb_str_new() with strlen().

use mrb_str_cat_lit for literals

use NAN and INFINITY macros

Make type casts safer

fix #1823

The macro str_to_mrb_float (strto[df]) converts a string to a number,
but these two macros can be used to directly get the special value.

The NAN macro requires quiet NaN support, but so does str_to_mrb_float.

This change also circumvents missing C99 support in Microsoft's C library.
Its (or ISO C90's) strtod doesn't parse "nan" or "inf".

Use sizeof(void*) instead of mrb_int size and extend embed string size.

two pool fixes

support linenoise in mirb

C4146 (unary minus operator applied to unsigned type, result still
unsigned)

Embed small string