Fix bad design with a slimy hack

AKA Check the fucking Travis-CI logs before you merge, damnit!

GCC wanted a function prototype becore declaration. This is noise: added a proto to silence it.

We do NOT want to drag the translations into the servers. So have each define a do-nothing implemenation of the deprecation function.

I don't CARE if this is gross and disgusting. It's the cleanest way to get us compiling again. It's only a few hours until we tag a release and I don't want to see yet another slip in the schedule due to a stupid mistake.

src/campaign_server/campaign_server.cpp

@@ -930,3 +930,6 @@ int main()
 
 	return 0;
 }
+
+void deprecated_message(const std::string&, int, const version_info&, const std::string&);
+void deprecated_message(const std::string&, int, const version_info&, const std::string&) {}

src/formula/formula.cpp

@@ -33,6 +33,8 @@ static lg::log_domain log_engine("engine");
 
 namespace utils {
 	namespace detail {
+		std::string evaluate_formula_impl(const std::string&);
+
 		std::string evaluate_formula_impl(const std::string& formula) {
 			try {
 				const wfl::formula form(formula);

src/server/server.cpp

@@ -2832,3 +2832,6 @@ int main(int argc, char** argv) {
 
 	return 0;
 }
+
+void deprecated_message(const std::string&, int, const version_info&, const std::string&);
+void deprecated_message(const std::string&, int, const version_info&, const std::string&) {}