* Updated the way authentication works on smb -- it's significantly cleaner now
* smb-enum-shares.nse gives significantly better output now (it checks if shares are writable)
* Added a script that checks if smbv2 is enabled on a server
* Added smb-psexec, a script for executing commands on a remote Windows server. I also included some default scripts, a compiled .exe to run everything, and a ton of documentation (in the form of NSEDoc)
* Added 'override' parameters to some of the functions in smb.lua, which lets the programmer override any field in an outgoing SMB packet without modifying smb.lua.
* Lots of random code cleanups in the smb-* scripts/libraries
