Relocated the Win32 style file finder to libdeng1

Updated the code for modern conventions, and added some Str utility
functions.
Unix: Relocated strupr/strlwr to libdeng1
Relocated dd_snprintf to libdeng1
Server|Windows: Server has no use for DirectInput

Fixes a build failure on Windows.
Revert "Fixed|Server|Windows: Server depends on DirectX"

This reverts commit 93ddc13ca1d240f2c449c9361a8da98d32762665.
Merge branch 'master' into material-cleanup
Fix server build