chore(output): add deprecation warning and update docs

Adds a deprecation warning for use of js attribute, updates docs with an example, removes the todo for style (support for this would require additional overhead for checking proper tokenization, whether or not style properties are closed with semicolon etc)
fix(security): Implements stronger remember me cookie strategy

This implements remember me tokens using a greater entropy pool,
replacing codes as users return to the site, and mitigating a
brute-force attack by introducing a delay when an invalid elggperm
cookie is given. For admins, the tokens are removed immediately.
fix(hhvm): hhvm compatibility

Reducing scrutinizer noise
fix(deprecated): fix container reference in getter function
fix(deprecated): fix incorrectly referenced variable
fix(deprecated): fix incorrectly referenced variable
fix(hhvm): hhvm compatibility

Reducing scrutinizer noise
fix(output): terminate attribute formatting early if attributes are not set

Reduce noise in logs by terminating elgg_format_attributes() early

Refs #6458
fix(views): use api to format ajax loader attributes

Reduce noise in logs by declaring variables and using elgg_format_attributes()

Refs #6458
fix(pages): comment out annotaton menu hook handler registration

Do not register a handler for "register","menu:annotation" hook - the callback function is not defined

Refs #6410
fix(views): define type variable

The view is passing a type to the tagcloud view, but it seems the only type that is supported is object
fix(groups): Linking the group name and adding the "discussion topics" breadcrumb.

Fixes #6449
Merge pull request #6457 from hypeJunction/1.8-todo

chore(output): add deprecation warning and update docs
Merge pull request #6461 from hypeJunction/noise

Cleaning up some log noise and scrutinizer bugs
Merge pull request #6597 from brettp/discussion_breadcrumbs

fix(groups): Linking the group name and adding the "discussion topics" b...
chore(htmlawed): Added more comprehensive tests for HTMLawed.

Fixes #6297
Merge pull request #6598 from brettp/htmlawed_tests

chore(htmlawed): Added more comprehensive tests for HTMLawed.
fix(views): rss w3c validation improvements
Merge pull request #6624 from beck24/rss-validation

fix(views): rss w3c validation improvements
Merged in remember_me (pull request #13)

Implements more secure remember me strategy for 1.8