Fixing padding on streams entry table.
Fixing bug with view_options in streams API.

This was overwriting the $stream_fields object, resulting in errors when custom view options were enabled.
Updating streams API entries view.

Updating to use the new standard lang_label() function plus misc code format updates.
Fixing semantic issue with Streams SQL builder.

The build_query() function accepted an array as a parameter but just used the class $sql variable instead. It should use the $sql variable, which it now does.

Also adding a proper reset_sql() function so we don't just reset it to a plain empty array.
Refining row parser join functionality.

This allows field types to do a join and add || as array delimiters. As an example, created_by has been baked into the row parser to be a join instead of a separate query.

This is on the edge of a new feature, but I consider the lack of advanced join functionality to be a bug more than anything, so I am counting it as a bug fix.

Closes #2179 
Fixing accidentally left in hardcoded database prefix.
Fixes to Streams row_m

Includes:

- Aliasing of created_by so we can have other joins with the users table in there.
- Field type hooks that allow field types to hook into the $sql.
- Fix so $stream_fields is only asked for once. It is still cached, but this just makes it easier.
Updating user field to use joins.
Simplifying the created_by join call in the get basic streams call.

This model call is used when we need basic data for the back end, so we are now just adding a join and using the user id and the username for displaying created_by.
Updating relationship field for new join syntax.

Now the relationship field adds to the join and grabs the join array and formats it for the plugin. Remains the same on the back end.
Minor code formmating
Merge remote-tracking branch 'upstream/2.2/develop' into 2.2/develop