[PATCH 3/5] include: Introduce ascii_strncasecmp helper and use it in msvcrt.

[Piotr Caban]

In tr_TR.UTF-8 locale tolower('I') != 'i' (this is not a bug in glibc,
tolower('I') is suppossed to return dotless i that is 2-byte long).
Because of that strcasemp("i", "I") returns that the strings are
different.

Another way of fixing it is to stop setting system locale for LC_CTYPE.

Spotted by Jactry Zeng.
Signed-off-by: Piotr Caban 
---
  dlls/msvcrt/locale.c   | 13 +++++++------
  dlls/msvcrt/mbcs.c     |  5 +++--
  dlls/msvcrt/string.c   |  7 ++++---
  include/wine/strings.h | 42 ++++++++++++++++++++++++++++++++++++++++++
  4 files changed, 56 insertions(+), 11 deletions(-)
  create mode 100644 include/wine/strings.h