Review exported non-internal functions

[hadley]

Just to make sure we're not advertising anything that we'd no longer recommend.

Functions to think about:

• release()
• reload()
• bash()
• wd()
• dev_mode()

[jennybc]

Thinking about #2489 made me realize that dev_mode() is arguably superseded at this point. Which might be good to formally declare.

OTOH I am still a keen user of release(). I like all those questions.