FEATURE: Allow manual excerpt to be defined past the beginning of the post

There is still a limitation that the span excerpt must begin before the post_excerpt_max_length.
FIX: Remove additional search code related to the up/down navigation

Removed additional search code that was related to the up/down navigation and their related tests.
https://meta.discourse.org/t/magic-search-code-for-keyboard-shortcuts/19563
UX: Remove background color from new badge. DRY up lots of repeated code
for rendering badges on topics.
Convert some application helpers to ES6 format.
Update Postgres.app instructions

- remove version number on git so we don't have to change it all the time
- update file path for postgresql.conf
- configure host for psql
- make the seed section its own section so its not embedded as a code snipppet
Add the integration test for search back using a fixture.
FIX: Prevent duplicate flags after undoing on the server side too.
Merge pull request #2747 from cpradio/remove-additional-search-code

FIX: Remove additional search code related to the up/down navigation
Prune dead code for search keyboard navigation in search, remove bad
tests.
Increase the contrast of the "new" text
FIX: Add .cooked class to composer preview

This should make any custom styling apply to both the rendered posts and
the composer equally, as long as a .topic-body parent or a #wmd-preview
parent is not specified.
UX: add dot before new topics via css
Merge pull request #2749 from riking/css-composer

FIX: Add .cooked class to composer preview
Merge pull request #2746 from mcwumbly/span-excerpt2

FEATURE: Allow manual excerpt to be defined past the beginning of the po...
Update DEVELOPMENT-OSX-NATIVE.md

- fixed typo with '/temp' to be '/tmp'
- removed capitalization if 'It' on same line since it's not the beginning of the sentence.
FIX: Remove `contents` class
Merge pull request #2748 from oblakeerickson/patch-1

Update Postgres.app instructions
"FIX": Add error reporting to NotifyMailingListSubscribers

Also skip unactivated users, which may actually fix this
FIX: under certain conditions, raw would change an cooked remain
  when editing a post
Merge pull request #2750 from riking/mailing-list-errors

"FIX": Add error reporting to NotifyMailingListSubscribers