topbar: Added active_if_page_is() function
topbar: Added active_if_page_is() function

TobiasLohner/SkyLines,shadowoneau/skylines,kerel-fs/skylines,dkm/skylines,snip/skylines,TobiasLohner/SkyLines,snip/skylines,RBE-Avionik/skylines,shadowoneau/skylines,RBE-Avionik/skylines,shadowoneau/skylines,dkm/skylines,Harry-R/skylines,kerel-fs/skylines,dkm/skylines,Harry-R/skylines,Turbo87/skylines,Turbo87/skylines,skylines-project/skylines,Harry-R/skylines,TobiasLohner/SkyLines,snip/skylines,skylines-project/skylines,RBE-Avionik/skylines,RBE-Avionik/skylines,Turbo87/skylines,kerel-fs/skylines,dkm/skylines,shadowoneau/skylines,skylines-project/skylines,Harry-R/skylines,Turbo87/skylines,skylines-project/skylines