Tested working with Roundcube 1.1.12 last week. Update README with th…

…is info in the install instructions and where to find patches for the daring people.

Or those that don't read instructions completely :).

README.md

@@ -33,6 +33,10 @@ but at the time of writing this (2016-03-07) it has not yet been completed.
 
 ## Installation
 
+Install the latest 1.1 branch version of Roundcube.
+This plugin is not compatible with 1.2 and later at this time.
+See the bottom of this README for where to find some patches in case you want to port this plugin to newer Roundcube releases.
+
 Clone the repository and copy `calendar` and `libcalendaring` to the `plugins` directory
 of your roundcube installation:
 
@@ -100,4 +104,5 @@ See `/var/www/htdocs/roundcube/logs/` for errors.
 ## Support
 
 There is none. Really. This code is not for the faint of heart.    
-Patches welcome.
+Patches welcome and some for Roundcube 1.2 are available in github issues and pull requests at
+https://github.com/fasterit/roundcube_calendar .