Version bump to 0.14.3.pre
Removed unnecessary validations

Writing group members is no longer a required field
Removed `None` checkbox options that added unnecessary validations
Publication proposal file attachments are no longer required for validation
Removed unneeded code
Better styling for errors (fix for bootstrap error bumping...)
Restyled errors and removed errors that will no longer occur
Removed deprecated code
Version 0.14.3 finalized