Added detection for the Kotlin language

lib/linguist/languages.yml

@@ -574,6 +574,12 @@ JavaScript:
   filenames:
   - Jakefile
 
+Kotlin:
+  type: programming
+  lexer: Kotlin
+  extensions:
+  - .kt
+  
 LLVM:
   extensions:
   - .ll

test/fixtures/Foo.kt

@@ -0,0 +1,47 @@
+package addressbook
+
+class Contact(
+  val name : String,
+  val emails : List<EmailAddress>,
+  val addresses : List<PostalAddress>,
+  val phonenums : List<PhoneNumber>
+)
+
+class EmailAddress(
+  val user : String,
+  val host : String
+)
+
+class PostalAddress(
+  val streetAddress : String,
+  val city : String,
+  val zip : String,
+  val state : USState?,
+  val country : Country
+) {
+   assert {(state == null) xor (country == Countries["US"]) }
+}
+
+class PhoneNumber(
+  val country : Country,
+  val areaCode : Int,
+  val number : Long
+)
+
+object Countries {
+  fun get(id : CountryID) : Country = countryTable[id]
+  
+  private var table : Map<String, Country>? = null
+  private val countryTable : Map<String, Country>
+    get() {
+      if (table == null) {
+        table = HashMap()
+        for (line in TextFile("countries.txt").lines(stripWhiteSpace = true)) {
+          table[line] = Country(line)
+        }
+      }
+      return table
+    }
+}
+
+class Country(val name : String)