KT-3729 Quick documentation support

#KT-3729 Fixed

idea/testData/editor/quickDoc/MethodFromStdLib.kt

@@ -0,0 +1,5 @@
+fun test() {
+    listOf(1, 2, 4).<caret>filter { it > 0 }
+}
+
+// INFO: <b>public</b> <b>fun</b> &lt;T> jet.Collection&lt;T&gt;.filter(predicate: (T) &rarr; jet.Boolean): jet.List&lt;T&gt; <i>defined in</i> kotlin<br/><p>Returns a list containing all elements which match the given *predicate*<br/></p>

idea/testData/editor/quickDoc/OnClassDeclarationWithNoPackage.kt

@@ -0,0 +1,6 @@
+/**
+ * Usefull comment
+ */
+class <caret>Some
+
+// INFO: <b>internal</b> <b>final</b> <b>class</b> Some <i>defined in</i> root package<br/><p>Usefull comment<br/></p>

idea/testData/editor/quickDoc/OnFunctionDeclarationWithPackage.kt

@@ -0,0 +1,15 @@
+package test
+
+/**
+
+ *
+ *
+ * Test function
+
+ *
+ * @param first - Some
+ * @param second - Other
+ */
+fun <caret>testFun(first: String, second: Int) = 12
+
+// INFO: <b>internal</b> <b>fun</b> testFun(first: jet.String, second: jet.Int): jet.Int <i>defined in</i> test<br/><p>Test function<br/><br/><br/><b>@param</b> - <i>first</i> - Some<br/><b>@param</b> - <i>second</i> - Other<br/></p>

idea/testData/editor/quickDoc/OnMethodUsage.kt

@@ -0,0 +1,15 @@
+/**
+ Some documentation
+
+ @param a - Some int
+ * @param b: String
+ */
+fun testMethod(a: Int, b: String) {
+
+}
+
+fun test() {
+    <caret>testMethod(1, "value")
+}
+
+// INFO: <b>internal</b> <b>fun</b> testMethod(a: jet.Int, b: jet.String): jet.Unit <i>defined in</i> root package<br/><p>Some documentation<br/><br/><b>@param</b> - <i>a</i> - Some int<br/><b>@param</b> - <i>b</i>: String<br/></p>