- added appveyor.yml with preparation for automatic github deloyment, just release builds are possible by available nmake makefile
- updated npp include files to v3.1 from https://github.com/npp-plugins/plugintemplate, modified PluginInterface.h to include menuCmdID.h as before
- changed makefile for x64 build
- updated bufferid references from INT -> LRESULT
- fixed issue https://notepad-plus-plus.org/community/topic/12558/session-manager-issue by usage of fix from https://github.com/pnedev/npp-session-manager