Update history docs.
Note - the omission of a mention of timezone was intentional. These were recorded as naive timestamps lacking timezone information in the first place.
The recent change to reconcile the history builtin command and function
broke an undocumented behavior of `history --delete`. This change
reinstates that behavior. It also adds an explicit `--exact` search mode
for the `--search` and `--delete` subcommands.
Fixes#3270
This fixes several problems with how the builtin `history` command handles
arguments. It now complains and refuses to do anything if the user specifies
incompatible actions (e.g., `--search` and `--clear`). It also fixes a
regression introduced by previous changes with regard to invocations that
don't explicitly specify `--search` or a search term.
Enhances the history man page to clarify the behavior of various options.
This change is already far larger than I like so unit tests will be added
in a separate commit.
Fixes#3224.
Note: This fixes only a couple problems with the interactive `history
--delete` command in the `history` function. The main problem will be
dealt with via issue #31.
