Log Message:
Update to 1.9.93:

megatools 1.9.93 - 2014-??-??
=============================

Added OpenSSL exemption to the license.

Fixes:

- megadf now returns correct values
- fixed path sanitization in mega_session_stat
- raised safety limit os size of POST responses from 32 to 256 MiB
- show progress when downloading folder using megadl
- optimized buffer allocation during donwload and upload
- report details of errors when stream callback fails to read/write file
- fix detection of convert executeable for preview generation
- allow to disable file previews