Re-merge fix for bug 2109.
The BLD.INF file in this directory builds only the following binaries:
libzcore.dll
libz.dll
In order to build these dll's against 9.1 OS release, the macro SYMBIAN_ZLIB_BUILD91 must be defined. This can be temporarily defined in epoc32/include/variant/Symbian_OS_v9.1.hrh. This causes libzcore_build91.mmp and zlib_build91.mmp to be used, which have backslashes instead of forward slashes for any paths, as required by 9.1 release.
Headers are exported to /epoc32/include/stdapis/