Added option to inject custom compile flags to compilation database (fixes #112)

src/config/config.h

@@ -222,6 +222,7 @@ struct config : public inheritable_diagram_options {
     // directory
     option<std::string> compilation_database_dir{
         "compilation_database_dir", "."};
+    option<std::vector<std::string>> add_compile_flags{"add_compile_flags"};
     option<std::string> output_directory{"output_directory"};
 
     option<std::map<std::string, diagram_template>> diagram_templates{

src/config/yaml_decoders.cc

@@ -585,6 +585,7 @@ template <> struct convert<config> {
         get_option(node, rhs.using_namespace);
         get_option(node, rhs.output_directory);
         get_option(node, rhs.compilation_database_dir);
+        get_option(node, rhs.add_compile_flags);
         get_option(node, rhs.include_relations_also_as_members);
         get_option(node, rhs.puml);
         get_option(node, rhs.generate_method_arguments);

src/config/yaml_emitters.cc

@@ -187,6 +187,7 @@ YAML::Emitter &operator<<(YAML::Emitter &out, const config &c)
 
     out << c.compilation_database_dir;
     out << c.output_directory;
+    out << c.add_compile_flags;
 
     out << dynamic_cast<const inheritable_diagram_options &>(c);