DoubleKeyValuePage: make PgUp and PgDown key go to prev/next page (#3601)
DoubleKeyValuePage: make PgUp and PgDown key go to prev/next page (#3601)


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