unicode table for cp437

There is a major bug in the cp437 to unicode translation table.  Char
0x7c is mapped to U+00a5 which is the Yen sign and wrong.  The right
mapping is U+00a6 (broken bar).

Furthermore, a mapping for U+00b4 (a widely used character) is missing
even though easily possible.

The patch fixes these, as well as it provides a few other useful
mappings.

The changes are as follows:

  0x0f (enhancement) enables a sort of currency symbol
  0x27 (bug) enables a sort of acute accent which is a widely used character
  0x44 (enhancement) enables a sort of icelandic capital letter eth
  0x7c (major bug) corrects mapping
  0xeb (enhancement) enables a sort of icelandic small letter eth
  0xee (enhancement) enables a sort of math 'element of'

Signed-off-by: Ingo Brueckl <ib@wupperonline.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>