configure.in:
Normally, 'configure' does only support "case-insensitive" collations for UTF-8 character sets.
However, a certain customer requires builds with a "case-sensitive" collation: 'utf8_general_cs'.
In order to do custom builds without manual patches, this value gets special handling in 'configure'.
Also, when it is given, the CPP symbol enabling the additional code is set.
mysys/charset-def.c:
Rename the CPP symbol needed for "UTF8-case-sensitive" collation from customer name to function.
strings/ctype-utf8.c:
Rename the CPP symbol needed for "UTF8-case-sensitive" collation from customer name to function.
