Instead, allow packagers to put a 'TOR_BUILD_TAG' field in the
server descriptor to indicate a platform-specific value, if they
need to. (According to weasel, this was his use for the git- tag
previously.)
This is part of 2988
For uname-based detection, we now give only the OS name (e.g.,
"Darwin", "Linux".) For Windows, we give only the Operating System
name as inferred from dw(Major|Minor)version, (e.g., "Windows XP",
"Windows 7"), and whether the VER_NT_SERVER flag is set.
For ticket 2988.
