Closes #300.

Fix bad encoding

Completion and jumping for empty needles

In python3, string.encode returns a byte array like:
b'14.1:\t/home/felix/devel/autojump'
This stops autojump from functioning at all.

This adds support for `j <tab>` and `j` without a needle to jump to the
first/best match.

Fixes https://github.com/joelthelion/autojump/issues/269

Since `pwd` is a resolved symlink, the comparison in `is_cwd` needs to
use the real path, too.

Fixes https://github.com/joelthelion/autojump/issues/281

With `j foo__` the first index is assumed now again.

Fixes https://github.com/joelthelion/autojump/issues/271

Fixes https://github.com/joelthelion/autojump/issues/274

With a custom install method (e.g. checkout in ~/.autojump), ~/.autojump/functions will not be present.

Closes #270.

Refer to #260.

This interferes with tab completion. Rather than add another behavior flag to
find_matches(), the calling location will add the default path.

Closes #245.

Fixes #244.

Closes #263.

Fixes https://github.com/joelthelion/autojump/issues/261

Fix calls to find_matches, which expects a list of needles.

Fixes https://github.com/joelthelion/autojump/issues/261

The check is to avoided since tab menu paths may be on slow IO devices (network
mounts, low power devices, etc).

Closes #258.

autojump.zsh: use `:h` modifier instead of `dirname`.

Ref: https://github.com/joelthelion/autojump/issues/249