Port Tor to work on Windows CE

Port Tor to work on Windows CE

Most of the changes here are switches to use APIs available on Windows
CE.  The most pervasive change is that Windows CE only provides the
wide-character ("FooW") variants of most of the windows function, and
doesn't support the older ASCII verions at all.

This patch will require use of the wcecompat library to get working
versions of the posix-style fd-based file IO functions.

[commit message by nickm]