KeyValuePage: make PgUp and PgDown key go to prev/next page (#3590)
KeyValuePage: make PgUp and PgDown key go to prev/next page (#3590)


poire-z/koreader,pazos/koreader,mwoz123/koreader,lgeek/koreader,NiLuJe/koreader,koreader/koreader,poire-z/koreader,Frenzie/koreader,Frenzie/koreader,Markismus/koreader,NiLuJe/koreader,apletnev/koreader,koreader/koreader,houqp/koreader,Hzj-jie/koreader,mihailim/koreader