fix notification: applied correct position offset calculations on adding/removing notifications
fix notification: applied correct position offset calculations on adding/removing notifications

Fix #156
jefvel/lumX,noikiy/lumX,b-cuts/lumX,noikiy/lumX,Ener-Getick/lumX,Ener-Getick/lumX,bright-sparks/lumX,clementprevot/lumX,jayaguilar/lumX,daniel-oliveiravas/lumX,hinablue/lumX,terradatum/lumX,jefvel/lumX,lumapps/lumX,jason588/lumX,jefvel/lumX,noikiy/lumX,bijeeshtk/lumx,b-cuts/lumX,terradatum/lumX,daniel-oliveiravas/lumX,jayaguilar/lumX,cupceavictor/lumX,bright-sparks/lumX,ezzye/write-to-be-heard,hinablue/lumX,itxd/lumX,jayaguilar/lumX,cupceavictor/lumX,jason588/lumX,clementprevot/lumX,cupceavictor/lumX,bijeeshtk/lumx,bright-sparks/lumX,ezzye/write-to-be-heard,Ener-Getick/lumX,b-cuts/lumX,clementprevot/lumX,noikiy/lumX,jason588/lumX,clementprevot/lumX,terradatum/lumX,daniel-oliveiravas/lumX,bijeeshtk/lumx,jefvel/lumX,itxd/lumX,terradatum/lumX,itxd/lumX,ezzye/write-to-be-heard,lumapps/lumX,lumapps/lumX,Ener-Getick/lumX,bijeeshtk/lumx,lumapps/lumX,jayaguilar/lumX,jason588/lumX,bright-sparks/lumX,itxd/lumX,cupceavictor/lumX,ezzye/write-to-be-heard,daniel-oliveiravas/lumX,hinablue/lumX,b-cuts/lumX,hinablue/lumX