Added license information.

Added PKG_BUILD_PARALLEL for faster compilation.

Change URLs to HTTPS.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Moved source folder in /sound folder, and changed all packages in the makefile
to be shown in Sound category (not in Sound subcategory of Utilities).
Removed a line calling a non-existent Package/alsa-utils/Default
and site URL to the package alsa-utils-tests.

Signed-off-by: Alberto Bursi <alberto.bursi@outlook.it>