[vdr] improving i18n-to-gettext.pl

Hi there!

This patch should improve i18n-to-gettext.pl to work with all plugins

1.It also lists i18n.h as there seem to be some plugin-writer putting translations there. 2. It also strips // comments being in lines without "," at the end. 3. it strips /* ... */ comments being in just one line 4. it strips /* ... */ comments spreading over multiple line 5. it just ignores #if and #endif lines (like used to make plugins compile with older vdr-versions which had less languages supported).

General question: Why is the locale dir called de_DE and not just de - as that seems what most other programs on my system do?

Matthias