Air Explorer 2.5.3, new version

List of changes: -Uploads of a large number of files are now faster and more reliable in Box. -Added 2 factor authentication for Mega. -New option in synchronizations to compare only files newer than a period. -Added a bandwidth scheduler, now it is possible to schedule the upload and download bandwidth limits depending on the day and hour. -Fixed Mega can not login in some accounts. -Pause and resume syncrhonizations. -Fixed uploading some files to Box did not work. -Added an option to execute a command or connect a network drive before a scheduled task is executed. -Fixed, the duration value in the synchronization report was sometimes wrong. -Exponential backoff retry control for Box. -Reduced the number of API requests in Google Drive. -Reduced the number of API requests in Box. -Reduced the number of API requests in Dropbox. -Reduced the number of API requests in OneDrive. -Better handling of 403 errors on Google Drive. -Folder structures are created faster on Google Drive. -Use less API requests when uploading a large number of files on Box. -Better handling of uploading a large number of small files to Dropbox. -Synchronization filter now supports many more rules. -Better error reporting of uploads and downloads. -Updated Hungarian translation (thanks to SEDATIVE). -Updated Chinese translation (thanks to GT Wang). -Updated Japanese translation (Thanks to Tilt). -Updated Brazilian Portuguese translation (Thanks to Igor). -Updated Russian translation (thanks to Timofey). -Updated Polish translation (Thanks to Janusz).