Style errors more conspicuously and consistently

[waldyrious]

Currently some errors are explicitly marked as errors:

Examples of messages explicitly marked as errors

Level0/www/osmapi.php

Line 66 in 390c810

$error = _('OAuth token was lost, please log in again.');

Level0/www/osmapi.php

Line 84 in 390c810

$error = 'Failed to create a changeset: '.$response->getBody();

Level0/www/osmapi.php

Line 90 in 390c810

$error = _('Could not aquire changeset id for a new changeset.');

...and these are styled in red:

Level0/www/page.php

Lines 13 to 15 in 390c810

	<?php if( $error ): ?>
	<p style="color: red;"><?=htmlspecialchars($error) ?></p>
	<?php endif ?>

However, other error messages are merely assigned to $messages:

Examples of error messages that are not marked as such

Level0/www/osmapi.php

Line 155 in 390c810

$messages[] = _('Failed to open XML stream');

Level0/www/osmapi.php

Line 253 in 390c810

$messages[] = sprintf(_('Download is incomplete, maximum of %d objects has been reached'), MAX_REQUEST_OBJECTS);

...so they appear as regular text in the page rendering, which can mask the fact that there was a problem.

These error messages should also be assigned to $error, or somehow made to be shown in a similar style to make sure the problem is noticed.