Add support for 'count ..' and 'find .. track X'
Error checking before type-cast
Changed track to track_no, fix code, add tests

Added testcases for track and count
Return MpdArgError if count parsing fails
Fix tabs->spaces and extra ')'
Fix small bug and fix test
Remove duplicate test group, merge it into existing
Merge branch 'develop' into feature/track_and_count
mpd: Fix import order
mpd: Formatting
mpd: Add 'find track ""' test to match search tests
local: Bring the corner case close to the condition
local: Order search filters consistently
local: Readd lost test assertion