- query spotify web api to check whether we are playing a song or an ad. deserialize answer using json (cf. SpotAnswer class)
- minor refactor (String -> string)
do not read the blocklist from disk each time it is accessed
minor cleanups
- remove unneeded 'using' directives
- use linq to find spotify in process list
minor cleanups
Merge pull request #4 from naspert/json_spotify_api

Few modifications
More accurate ad detection - now uses Spotify and iTunes API's
Fix low cpu priority bug