Merged in my changes from nmap-smb. The primary changes are:

* 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

nselib/data/psexec/experimental.lua

@@ -0,0 +1,25 @@
+module(... or "experimental", package.seeall)
+---This is the configuration file for modules that aren't quite ready for prime
+-- time yet. 
+
+
+-- Any variable in the 'config' table in smb-psexec.nse can be overriden in the 
+-- 'overrides' table. Most of them are not really recommended, such as the host, 
+-- key, etc.
+overrides = {}
+--overrides.timeout = 40
+
+modules = {}
+local mod
+
+
+-- I can't get fport to work for me, so I'm going to leave this one in 'experimental' for now
+--mod = {}
+--mod.upload           = true
+--mod.name             = "Fport"
+--mod.program          = "Fport.exe"
+--mod.url              = "http://www.foundstone.com/us/resources/proddesc/fport.htm"
+--mod.maxtime          = 1
+--mod.noblank          = true
+--table.insert(modules, mod)
+