The attached patch makes names in ob-shell.el use the same prefix
"org-babel-shell-" (along with a few similar minor consistency
updates).

Without the patch, three naming conventions exist:

- org-babel-shell
- org-babel-sh
- ob-shell <----- that's my fault :)

The Org Babel shell library was previously called "ob-sh.el" and later
changed to "ob-shell.el".  When this happened, the meaning of the "sh"
changed.  When the library was called "ob-sh.el", "sh" meant a generic
shell.  When the library was renamed "ob-shell.el", "shell" took on
the role of a generic shell and "sh" became a reference to /bin/sh.

The  current "sh" names are generic and not specific to "/bin/sh" or
something like the Bourne Shell.  The patch updates all "sh" names
to "shell".

When I submitted my async changes, I introduced an "ob-shell" prefix.
Emacs names typically begin with the library name and I just continued
in that style.  Org is different, however, because it's the "org-"
library.  For sub-libraries, like Babel, the convention is
"org-babel-<language>-".  ob-shell.el is unusual in that it supports
multiple languages.  However, ob-C.el also supports multiple languages
and uses "org-babel-<language>-".  I find there's no confusion using
this style.

FWIW, I found it confusing when I first started learning the Org code
base that the naming convention is at the "org-" level and not at the
library level (for example, "ob-shell-").  A large part of my
confusion, I think, was simply inconsistencies within ob-shell.

It's late for me, so rather than commit in a rush, I'm posting this
for review/comment.  The tests pass and I think I preserved all the
API function names (like org-babel-execute:template).

Thoughts?

--
Matt Trzcinski
Emacs Org contributor (ob-shell)
Learn more about Org mode at https://orgmode.org
Support Org development at https://liberapay.com/org-mode