add cache logic for channels: get_channels, del_channels, has_channels; fix code of removing undef item in Channel.pm
it has not passed testing t/06_command/channel_operation.t
Checking in changes prior to tagging of version v3.1.5.

Changelog diff is:

diff --git a/Changes b/Changes
index 6fd999a..1b8bee4 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,16 @@ Revision history for Perl extension Uc-IrcGateway

 {{$NEXT}}

+v3.1.5 2014-01-04T00:52:19Z
+
+    - add cache logic for channels:
+
+        - get_channels, del_channels and has_channel use cached object
+
+    - fixed code of removing undef item in "Channel->get_users".
+
+    - add Build.bat in .gitignore for Windows.
+
 v3.1.4 2013-12-30T21:25:55Z

     bugfix: these DBI options are not enabled: RaiseError, PrintError, AutoCommit