First stab at the ability to compile puttytel.exe, an SSH-free

First stab at the ability to compile puttytel.exe, an SSH-free
variant which is patent-safe in the US and legal in France and
Russia. This is a horrible hack in some ways: it's shown up serious
deficiencies in the module boundaries. Needs further work, probably
once the SSH implementations are recombined.

[originally from svn r410]