Add a os.execute-like function for calling execl
Add a os.execute-like function for calling execl

It is safer than using os.execute when passing filenames as arguments

Hzj-jie/koreader-base,frankyifei/koreader-base,apletnev/koreader-base,apletnev/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,Hzj-jie/koreader-base,koreader/koreader-base,apletnev/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,koreader/koreader-base,koreader/koreader-base,apletnev/koreader-base,Frenzie/koreader-base,houqp/koreader-base,frankyifei/koreader-base,frankyifei/koreader-base,houqp/koreader-base,houqp/koreader-base,NiLuJe/koreader-base,houqp/koreader-base,Hzj-jie/koreader-base,Hzj-jie/koreader-base,NiLuJe/koreader-base,frankyifei/koreader-base,Frenzie/koreader-base,NiLuJe/koreader-base