Introduce message renderer

This new class replaces all existing server side message
rendering helpers and is the new global entry point for such
needs. All models with relevant fields now expose an instance
of MessageRenderer for those. MessageRenderer acts as
gateway between the existing processing solutions for markdown,
mentions and tags and provides a very flexible interface for
all output needs. This makes the API to obtain a message
in a certain format clear. As a result of centralizing the
processing a lot of duplication is eliminated. Centralizing
the message processing also makes it clear where to change
its behaviour, add new representations and what options
are already available.
use uuids for guid generation
Add warning to script/server if curl does not support AsyncDNS
Refactored poll_view.js
Make poll to be compatible with bootstrap
updated 138 locale files [ci skip]
Merge pull request #4894 from hpetru/4893-poll-in-spv

Add poll for single post view
I update design for poll in post stream
Fix tr 

The translation 'türk' is ethnicity / nationality. change to language, türkçe.
Merge pull request #4897 from hpetru/update-poll-view-in-stream

I update design for poll in post stream
Merge pull request #4898 from mehmetaergun/patch-1

Fix tr in locale settings
Merge branch 'develop' of github.com:diaspora/diaspora into develop
Add poll in post preview
Merge pull request #4899 from hpetru/poll-in-post-preview

Add poll in post preview
drop rmagick, fixes #4594

This breaks the screenshot tool.

RMagick no longer compiles on recent ImageMagicks that have HDRI
support enabled.
Merge pull request #4900 from MrZYX/drop_rmagick

Drop rmagick
Fixed 4903 and not render vote form when user is not logged
Fix missing translation in #4905.
Merge pull request #4907 from goobertron/poll_i18n_fix

Fix missing translation in #4905
Merge pull request #4906 from hpetru/4903-poll-crash-spv

Fixed 4903 and not render vote form when user is not logged