Add current file in bug report attachments.

Parsing of special html entities (like > or <) improved too.
Remove options from contact form.

Those options were confusing and unnecessary.
Display all changes since last major version in changelog.
Version 13.04.2
Improve changelog.
Version 13.04.3
Add word wrap in About dialog.
Version 13.04.4
Fix bug when starting some modules for the first time.

Default parameters were not defined when preferences.xml was not loaded.
[Tablatex] Add spinbox in GUI to select decimals precision for tabvar and tabval.
Version 13.04.5