Terminate script after redirect

* roma/roma.php (redirectBrowserHeader, redirectToStart): Terminate
  script after redirect.

Otherwise the script might keep running, leading to strange error
messages.

Example: If one choses roma_mode_newCustomization, the script unsets
the object property holding the current customization and redirects to
the web application's start page. If the script is not terminated,
then it tries to persist the customization in session at the end of
roma::run().

But because the property was removed the log file records errors such
as:

,----
| [Tue Oct 28 09:37:23 2014] [error] PHP Notice:  Undefined property: roma::$m_oRomaDom in /usr/share/tei-roma/roma/roma.php on line 551
| [Tue Oct 28 09:37:23 2014] [error] PHP Fatal error:  Call to a member function SaveXML() on a non-object in /usr/share/tei-roma/roma/roma.php on line 551
`----
Merge branch 't/terminate-after-redirect' into bugfixed

Conflicts:
	roma/roma.php