Fix versions and add 'modern' configuration

dub.sdl

@@ -10,3 +10,10 @@ dependency "sdlang-d" version="~>0.10.5"
 preGenerateCommands "./generate-package-version.fish"
 versions "VibeDefaultMain"
 targetPath "out"
+
+configuration "application" {
+}
+
+configuration "modern" {
+    versions "BasicFixes" "SupportTLS"
+}

source/ircd/versions.d

@@ -3,27 +3,30 @@ module ircd.versions;
 /++
     Supported versions:
 
-    * NotStrict: enabled when any versions are enabled that disable RFC-strictness (i.e. any of the following)
+    * SupportTLS: compile with TLS support
-    * SupportTLS: compile with TLS support, enabled when NotStrict is on
     * BasicFixes: enable basic/sanity RFC fixes
     * MaxNickLengthConfigurable: makes max nick length configurable
     * Modern: enable all versions
+
+    (* NotStrict: enabled when any versions are enabled that disable RFC-strictness, i.e. any of the above)
 +/
 
+version (Modern)
+{
+    version = SupportTLS;
+    version = BasicFixes;
+    version = MaxNickLengthConfigurable;
+}
+
 version (SupportTLS) version = NotStrict;
 version (BasicFixes) version = NotStrict;
 version (MaxNickLengthConfigurable) version = NotStrict;
 
 version (NotStrict)
 {
-    version = SupportTLS;
+    version (SupportTLS) {}
-}
+    else
-
+    {
-version (Modern)
+        static assert(false, "TLS support must be enabled if any non-strict versions are enabled.");
-{
+    }
-    version = NotStrict;
-
-    version = SupportTLS;
-    version = BasicFixes;
-    version = MaxNickLengthConfigurable;
 }