[core] use location.hash for start dirctory

If location.hash is "#elf_`file.hash`", use `file.hash` as start dirctory.
[cmd:info] add command options `{nullUrlDirLinkSelf : true}`

`nullUrlDirLinkSelf : true` that make link that opens directory in elFinder, if "file.url" is null.
Merge branch '2.x' into 2.1_n