client: fix 64-bit crash in process_send due to signed/unsigned foo
utils: collection_add don't double capacity but instead increase by a fixed amount
device: make device_list access thread safe
device/client: make device_get_list() allocate the result buffer itself

Using device_get_count() and device_get_list() separately can return different
device counts in case there are devices added to the list inbetween these two
function calls. To prevent this, device_get_list() will allocate the buffer by
itself.
device: suppress "No connection for device" if TH_RST is set
removed trailing \n from usbmuxd_log() messages
utils: add new collection_copy() function
device: reduce locking time inside device_get_list() and device_get_count()
client: fix realloc in send_pkt() that made the buffer smaller instead of larger