* Update CHANGELOG with latest updates
* Update version string in docs

Previously executing `:AuditoryOn` and `:AuditoryOff` would always do
the thing they're supposed to do regardless of whether Auditory was
already on or off.

This caused errors because things got messed up when trying to
double assign the mappings and double unmap the mappings.

Now check for the status of the `g:auditory_on` flag before turning
Auditory on or off.

Pressing `G` would bring the cursor to the first line in the buffer
instead of the last line in the buffer because the count in the mapping
was always `v:count1`. This meant that the `G` mapping behaved like `1G`
when no count was specified.

This change fixes the `G` mapping to use `v:count` so that it goes to
the last line in the buffer as expected.

We also add support for arbitrary mappings to choose whether they want
to be `v:count` or `v:count1` depending on what value is specified in
the mapping dict.

* Update CHANGELOG
* Update version string in docs