added the community name to item.title

[mojoaxel]

This adds the Community-name to the Titel of each item. Here is an example:

current:

<title>nächstes Freifunktreffen 2. Februar</title>
<title>Freifunktreffen im Februar</title>

new:

<title>[Freifunk Frankfurt am Main] nächstes Freifunktreffen 2. Februar</title>
<title>[Freifunk Rothenburg] Freifunktreffen im Februar</title>

It looks like this is an alternative or addition to #4

[andibraeu]

could we make that feature configurable? Some tools are designed to use the source tag, e.g. on freifunk.net