If type is specified but not index, default to _all

These endpoints should use the `_all` special index if a type is
specified but no index.

src/Elasticsearch/Endpoints/Count.php

@@ -52,6 +52,8 @@ protected function getURI()
 
         if (isset($index) === true && isset($type) === true) {
             $uri = "/$index/$type/_count";
+        } elseif (isset($type) === true) {
+            $uri = "/_all/$type/_count";
         } elseif (isset($index) === true) {
             $uri = "/$index/_count";
         }

src/Elasticsearch/Endpoints/Mget.php

@@ -54,6 +54,8 @@ protected function getURI()
             $uri = "/$index/$type/_mget";
         } elseif (isset($index) === true) {
             $uri = "/$index/_mget";
+        } elseif (isset($type) === true) {
+            $uri = "/_all/$type/_mget";
         }
 
         return $uri;

src/Elasticsearch/Endpoints/Msearch.php

@@ -75,6 +75,8 @@ protected function getURI()
             $uri = "/$index/$type/_msearch";
         } elseif (isset($index) === true) {
             $uri = "/$index/_msearch";
+        } elseif (isset($type) === true) {
+            $uri = "/_all/$type/_msearch";
         }
 
         return $uri;

src/Elasticsearch/Endpoints/Search.php

@@ -35,14 +35,7 @@ public function setBody($body)
             return $this;
         }
 
-        if (is_string($body) === true || is_array($body) === true) {
-            $this->body = $body;
-        } else {
-            throw new InvalidArgumentException(
-                'Query must be a string or array'
-            );
-        }
-
+        $this->body = $body;
         return $this;
     }
 
@@ -61,6 +54,8 @@ protected function getURI()
             $uri = "/$index/$type/_search";
         } elseif (isset($index) === true) {
             $uri = "/$index/_search";
+        } elseif (isset($type) === true) {
+            $uri = "/_all/$type/_search";
         }
 
         return $uri;