Whitespace cleanup: Remove all multiple newlines

This patch removes all occurrences of double and triple
newlines.

Command used for this:
find .  -type d \( -name ffmpeg \) -prune -o \
        -regex '\(.*\.[hc]\|.*\.cc\)' \
        -a -not -name 'adrian-aec.*' -a -not \
        -name reserve.c -a -not -name 'rtkit.*' \
        -exec sed -i -e '/^$/{N;s/^\n$//}' {} \;

Two passes were needed to remove triple newlines.
The excluded files are mirrored files from external sources.

src/modules/module-rygel-media-server.c

@@ -160,7 +160,6 @@ PA_MODULE_USAGE("display_name=<UPnP Media Server name>");
     " </interface>"                                                     \
     "</node>"
 
-
 static const char* const valid_modargs[] = {
     "display_name",
     NULL