* lisp/ob-shell.el (org-babel-shell-initialize): force blocks to
always use the specified shell language
Sessions are initialized using `shell'. The `shell' command checks
`explicit-shell-file-name' for file to use before checking other
variables, like `shell-file-name'. Previously, only `shell-file-name'
was set. So, if the user had set the `explicit-shell-file-name',
session blocks would use that whereas non-session blocks would use
`shell-file-name', resulting in inconsistent behavior. This change
sets both variables so that even if the user changes the
`explicit-shell-file-name' or `shell-file-name', blocks will only use
the shell language specified by the block.
TINYCHANGE
