bug fix: signal ViewRecalculate event after panning
bug fix: signal ViewRecalculate event after panning

This make sure ReaderPaging get correct visible_area when
turnning to previous page.

houqp/koreader-base,NiLuJe/koreader-base,Hzj-jie/koreader-base,koreader/koreader-base,Hzj-jie/koreader,Frenzie/koreader,koreader/koreader-base,Frenzie/koreader,ashhher3/koreader,NickSavage/koreader,pazos/koreader,apletnev/koreader-base,NiLuJe/koreader-base,Frenzie/koreader-base,apletnev/koreader-base,mihailim/koreader,noname007/koreader,robert00s/koreader,Hzj-jie/koreader-base,houqp/koreader,mwoz123/koreader,NiLuJe/koreader,Frenzie/koreader-base,Hzj-jie/koreader-base,chihyang/koreader,houqp/koreader-base,Frenzie/koreader-base,apletnev/koreader-base,ashang/koreader,lgeek/koreader,apletnev/koreader,Hzj-jie/koreader-base,koreader/koreader,poire-z/koreader,koreader/koreader-base,NiLuJe/koreader-base,frankyifei/koreader-base,frankyifei/koreader-base,houqp/koreader-base,poire-z/koreader,houqp/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,Markismus/koreader,frankyifei/koreader-base,apletnev/koreader-base,NiLuJe/koreader,chrox/koreader,koreader/koreader,frankyifei/koreader-base,frankyifei/koreader,Frenzie/koreader-base