Redmine#3279: add storejson() function
Merge pull request #1052 from tzz/tzz/1032-read-proc-and-sys-specially

Redmine#1032: fix 1-byte read issue
Merge pull request #1049 from tzz/feature/3279-storejson

Redmine#3279: add storejson() function
Redmine#1032: add 0 maxsize read to empty file