- Move the logging logic from preview,sound download and pack download into one single function
- removed declaration of 'do_log' from sounds/views.py (l:226) since it was unused.
- code cleaning in search/views.py : instead of having a if/else statement, used of dict.setdefault to initialize/append to query_chain key
- changed DO_LOG_CLICKTHROUGH_DATA to LOG_CLICKTHROUGH_DATA
- changed .replace("_alt","") to .replace("data/previews_alt/","data/previews/")
- removed the mp3_alt and ogg_alt and added a url_alt inside the mp3 and ogg in the locations function (to avoid redundancy)