Windows: Export a few more functions to afsauthent and afsrpc

Windows: Export a few more functions to afsauthent and afsrpc

The following exports are added:

libafsauthent:
    afsconf_SetExtendedCellInfo
    afsconf_PickClientSecObj
    afsconf_SawCell
    ka_PrintBytes
    ka_KeyIsZero

libafsrpc:
    initialize_RXK_error_table

Those functions are referenced by the bos code.

Change-Id: I26898070c8e9dc7cac53f13c49dadf28d58457f4
Reviewed-on: http://gerrit.openafs.org/8154
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>