Bump version to 1.9.91
Megadf - fix unsigned overflow when server reports 0 total space

- Add new options --mb --gb --free --used --total
Move do_discobnnect before socket client reconfiguration
Implemented --debug option
Win32: Drop requirement for manual setup of GIO_EXTRA_MODULES

- and ca-certificates.crt
Enable CA validation
Fix compilation on FreeBSD by adding --enable-warnings
Add note that on FreeBSD GNU make must be used to build the tools
Fix typedef redefinitions
Fix megals --names logic
Change header style in megals
Fix megareg error messages
megaput: --no-progress support
megaget: --no-progress support, streaming support via --path -

- And improved parameter checking
megadl: --no-progress support, streaming support via --path -

- And improved parameter checking
Fix mega_session_dl streaming mode segfault
megasync: --no-progress support
megamkdir/megarm: Check for required arguments
megamv: Remove example usage from the error output
Updated sjson with new features