Fix various new compiler warnings.

terminalfunctions.cc: set_if_available() was undeclared.
Fix printf() wint_t/wchar_t warnings.
mosh-server.cc: Fix warning for side effects inside typeid().

Signed-off-by: John Hood <cgull@glup.org>

src/terminal/terminalframebuffer.cc

@@ -589,7 +589,7 @@ bool Cell::compare( const Cell &other ) const
   if ( !contents_match( other ) ) {
     ret = true;
     fprintf( stderr, "Contents: %lc vs. %lc\n",
-	     debug_contents(), other.debug_contents() );
+	     (wint_t)debug_contents(), (wint_t)other.debug_contents() );
   }
 
   if ( fallback != other.fallback ) {