RUBY-17811: Finish ruby-yaml extraction.

Common I18n api extracted so plain ruby I18n may work without yaml plugin.
 YAML spellchecker moved to yaml plugin.

plugins/yaml/resources/META-INF/plugin.xml

@@ -27,6 +27,10 @@
     <lang.elementManipulator forClass="org.jetbrains.yaml.psi.impl.YAMLScalarImpl"
                              implementationClass="org.jetbrains.yaml.psi.impl.YAMLScalarElementManipulator"/>
   </extensions>
+  
+  <extensions defaultExtensionNs="com.intellij.spellchecker">
+    <support language="yaml" implementationClass="org.jetbrains.yaml.YAMLSpellcheckerStrategy"/>
+  </extensions>
 
 
 </idea-plugin>

plugins/yaml/src/org/jetbrains/yaml/YAMLSpellcheckerStrategy.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jetbrains.yaml;
+
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.tree.IElementType;
+import com.intellij.spellchecker.tokenizer.SpellcheckingStrategy;
+import com.intellij.spellchecker.tokenizer.Tokenizer;
+import org.jetbrains.annotations.NotNull;
+
+public class YAMLSpellcheckerStrategy extends SpellcheckingStrategy {
+  @NotNull
+  @Override
+  public Tokenizer getTokenizer(final PsiElement element) {
+    final ASTNode node = element.getNode();
+    if (node != null){
+      final IElementType type = node.getElementType();
+      if (type == YAMLTokenTypes.SCALAR_TEXT ||
+          type == YAMLTokenTypes.SCALAR_STRING ||
+          type == YAMLTokenTypes.SCALAR_DSTRING ||
+          type == YAMLTokenTypes.COMMENT) {
+        return TEXT_TOKENIZER;
+      }
+    }
+    return super.getTokenizer(element);
+  }
+}