added configurable static libstdc++ linking
added configurable static libstdc++ linking

you can now point to a static libstdc++:

make STATICLIBSTDCPP=/home/hw/kindle-sysroot/usr/lib/libstdc++.a

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