Various fixes

* Add MIME types for file attachments
* Restore translatability to mood phrases
* Prevent casting of "false" in html2plain
* Allow attachments with a comma in the filename
* Fix/optimize ACL img data-src jQuery search
* Fix bug when uploading files with a comma in the name using Chrome/Chromium
* Babel nicer output formatting
* Remove obsolete "plaintext" check in mod/parse_url
* Restore TinyMCE live insertion of images
* Smarty conversion script: add --no-header option to suppress warning headers in Smarty template files