utf8mb4 support

gistfile1.diff

diff --git a/lib/mysql2/client.rb b/lib/mysql2/client.rb
index 20ed442..8497ca0 100644
--- a/lib/mysql2/client.rb
+++ b/lib/mysql2/client.rb
@@ -87,6 +87,7 @@ module Mysql2
         "ucs2"     => Encoding::UTF_16BE,
         "ujis"     => Encoding::EucJP_ms,
         "utf8"     => Encoding::UTF_8,
+        "utf8mb4"  => Encoding::UTF_8,
       }
 
       MYSQL_CHARSET_MAP = {
@@ -134,6 +135,7 @@ module Mysql2
         42 => {:name => "latin7",   :collation => "latin7_general_cs"},
         43 => {:name => "macce",    :collation => "macce_bin"},
         44 => {:name => "cp1250",   :collation => "cp1250_croatian_ci"},
+        45 => {:name => "utf8mb4",  :collation => "utf8mb4_general_ci"},
         47 => {:name => "latin1",   :collation => "latin1_bin"},
         48 => {:name => "latin1",   :collation => "latin1_general_ci"},
         49 => {:name => "latin1",   :collation => "latin1_general_cs"},