* Implement `history search --reverse`
It should be possible to have `history search` output ordered oldest to
newest like nearly every other shell including bash, ksh, zsh, and csh.
We can't make this the default because too many people expect the
current behavior. This simply makes it possible for people to define
their own abbreviations or functions that provide behavior they are
likely used to if they are transitioning to fish from another shell.
This also fixes a bug in the `history` function with respect to how it
handles the `-n` / `--max` flag.
Fixes#4354
* Fix comment for format_history_record()
Using the FISH_HISTFILE variable will let people customise the session
to use for the history file. The resulting history file is:
`$XDG_DATA_HOME/fish/name_history`
Where `name` is the name of the session. The default value is `fish`
which results in the current history file.
If it's set to an empty string, the history will not be stored to a
file.
Fixes#102
Running the tests on travis revealed that some compilers (or at least
with some options) call the wrong struct constructor if there is more
than one struct with the same name but differing definitions.
