http access: Use EnsureUTF8() on the ICY strings. Avoids "illegal byte sequence" warnings and the like such as in #1772

pda gui: Set prio to 0, so it is not eligible for automatic selection. This is bad since it's a GTK module, and with our Qt switch and demise of wxGTK module, this module might be selected more often. It is not for the average user, and 0 tested under 0.9.0. Relates to #1798

+ a few cosmetics

Let's don't by pass the defaults here. This also fixes an thread error at exit.