Better api generation

Things to consider:

• breaking changes (removed imports), so up minor version, because we are still not in 1.0

src/main/jastadd/backend/API.jadd

@@ -13,21 +13,21 @@ aspect BackendAPI {
   }
 
   public void RelationComponent.generateAPI(StringBuilder sb) {
-    if (otherSide().isNavigable()) {
+    if (opposite().isNavigable()) {
       if (multiplicityOne() || multiplicityOpt()) {
         generateGetOne(sb);
-        if (otherSide().multiplicityOne() || otherSide().multiplicityOpt()) {
+        if (opposite().multiplicityOne() || opposite().multiplicityOpt()) {
           generateBiOneOne(sb);
-        } else if (otherSide().multiplicityMany()) {
+        } else if (opposite().multiplicityMany()) {
           generateBiOneMany(sb);
         }
         if (isOpt()) {
           generateExtraOptAPI(sb);
         }
       } else if (multiplicityMany()) {
-        if (otherSide().multiplicityOne() || otherSide().multiplicityOpt()) {
+        if (opposite().multiplicityOne() || opposite().multiplicityOpt()) {
           generateBiManyOne(sb);
-        } else if (otherSide().multiplicityMany()) {
+        } else if (opposite().multiplicityMany()) {
           generateBiManyMany(sb);
         }
       }