put a request to report a date and time to the problem message
rename and move the constant of maximum note length
fix memory leak with mkpolylines
display the selected date atop of the corresponding button; save the query date range to userDefaults; dismiss the datepickers before start of the query
remove unused import
change title color of Recording button; set background image of Recording button
highlight the selected state of date buttons
Merge branch 'master' of github.com:pryv/mobile-position-ios