(ITS#5215) Use of ln is hardcoded in some files

[emmanuel.duru@atosorigin.com]

Full_Name: Emmanuel Duru
Version: 2.3.38
OS: Windows
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (195.68.44.148)


configure allows the use of "cp" instead of "ln", but the build/shtool tool uses
a hardcoded "ln" (line 1266).
Some makefiles (libraries/liblunicode, libraries/libldap_r and
servers/slapd/back-hdb) use a hardcoded "-s" option. This is a problem on
Windows because in cygwin environment "cp -s" behaves the same way as "ln -s".
The use of "ln" is not welcome here because it creates a Windows shortcut, which
is not understood by mingw compiler.