Log Message:
Update contao42 to 4.2.1.

### 4.2.1 (2016-07-15)

 * Strip soft hyphens when indexing a page (see contao/core#8389).
 * Do not run the command scheduler if the installation is incomplete (see #541).
 * Do not index randomly ordered image galleries.
 * Fix the filter menu layout on mobile devices.
 * Provide the back end fonts in different variants (see #523).
 * Fix the message markup in the member templates.
 * Correctly load the language strings in the pretty error screen listener.