Runtime: wx.app.mainLoop and twisted reactor now share main thread with runtime.Worker.
This fixes exception when invoking python interactive shell from Runtime's tray
icon right-click menu.
Probably a consequence of wxPython upgrade, together with initial bad idea to
move wx.app.mainloop in non-main thread.
<xsd:attribute name="Compiler" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="CFLAGS" type="xsd:string" use="optional" default=""/>
<xsd:attribute name="Linker" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="LDFLAGS" type="xsd:string" use="optional" default=""/>