Merge pull request 36 from @jamessan

Closes #36.
Docs: update hunk jumping
New option: g:signify_disable_by_default

You can choose to disable Sy by default now. You can enable it anytime
via :SignifyToggle (or the default mapping: <leader>gt).

Closes #34.
Bump to 1.9
Echomsg won't interpret unprintable characters
Fix wipeout error

Closes #38.
Put hl group linking into a function
Setup hl groups on VimEnter
Indicate deleted lines for ChangeDelete signs
Docs: simplify sign explanation
README: remove 2.0 note

It will be released when it's ready!
README: remove sign_change_delete var
Doc: update 'local additions' header
Docs: "amount" -> "number"
Docs: use full sentences
Docs: minor corrections
Gitignore: update
Add support for accurev