Feature Request: specify non-default themerc from bash script

Submitted by Colin Keenan

Assigned to Olivier Fourdan @olivier

Link to original bug (#11171)

Description

I want to be able to launch just one window using a different theme than my default theme. I want to be able to specify the themerc file that xfwm4 will use for the window decorations, in a way similar to how gtk allows specification of the gtkrc file using an environment variable.