Add doxygen, begin documenting, kitrap0d tidy

* Added the doxygen binaries and configuration.
* Added a `make docs` which generates documentation to the `docs` folder.
* Added some documentation to various areas of the source that I was
  working with. Over time I'll be adding more and more rather than trying
  to do it all in one hit.
* Refactored the kitrap0d code a bit to try to reduce code size.
More documnetation work
Even more docs
Add webcam thread to avoid COM-related crash

Webcam code was sometimes causing crashes in Meterpreter when attempting
to stop the camera after a frame had been captured. This appeared to be
because the thread that started the capture was not the same thread that
ended it.

CoInitialize() and CoUninitialize() need to be called on the same thread
and objects created on one thread need to be released on the same thread.
This change results in a new worker thread that is used for the lifetime
of the capture, and the callers have to interact with this thread via
basic threading events.

This is currently "proof of concept" code, rather than production-ready
code. The goal is to see if it solves the issue on the known targets
before tidying it up and locking it down for release.
Remove boiler extension and create 'bare' extension

The boiler extension wasn't used and was old so it was removed. I've added
a new "bare" extension which is, as it says, just bare and doesn't do
anything. This can be used to create new extension projets just by copying
and pasting, then editing a couple of small things.

This will be added to the documentation.
New ext docs, remove boiler from solution

Documentation now includes how to create a new extension using the bare
extension as a sample.
Doc changes, project fixes
Fix debug build of various components

No idea why they were broken, but they shouldn't have been. This fixes
them up and tidies a few other things up, especially the guts of the
stdapi project.
Documented base.* and core.*

Big job, this documentation lark. Also modified the prototype the
packet_is_tlv_null_terminated function, which used to take a Packet
instance as well as the TLV, but never used the packet in its
implementation.
Update .gitignore to avoid conflict
Remove strcpy calls, proper use of strncpy/strcpy_s

Replaced all usages of `strcpy` with `strncpy` or `strcpy_s`.

Make sure that all usages of `strncpy` specified the correct buffer size.
Resolve PR #31 conflict

Conflicts:
	.gitignore
Merging https://github.com/OJ/meterpreter/pull/1
Fix exclude config to ignore unnecessary content

Updated to use `EXCLUDE_PATTERNS` instead of `EXCLUDE_PATHS`. This
properly excludes the source of the libraries we use and also the
generated output on POSIX.

Thanks again to @jlee-r7 for the catch.
Land #31, doxygen
Land #29, new 'bare' extension

Replaces 'boiler'
Whitespace
Fix railgun crash on XP SP3

Fix issue where the railgun API was relyling on FormatMessage returning a
valid pointer when the error is `ERROR_SUCCESS`. On some platforms, such
as XP SP3, the function would return a NULL pointer for this case. This
fix makes sure that in the case of a NULL pointer the error message is set
to a value that matches that found on other platforms.

[FixRM 8505]
Command refactor for clean shutdown + inline calls

This work contains a bunch of changes around command dispatching. The
goals for this bit of work were to:

* Provide the ability for commands to be executed on the same thread as
  the server rather than always creating new threads and executing them on
  those threads.
* Have the means for _special_ commands, such as `exit` and `migrate` to
  shut down the server cleanly without having to rely on signalling across
  threads or by doing brutal thread termination via shared global handles.
  This should not only fix the dirty shutdown problem on Windows which
  leaves tasks dangling (or based on the prior attempt at fixing, crashing
  stuff as well), it should also help clean up the shutdown process in
  POSIX.

These changes hit a very important part of Meterpreter and so should be
reviewed with intense scrutnity. I expect this PR to garner a log of
critique and most likely a number of changes before being included in the
main line.

The `PacketDispatcher` was modified to include a new function pointer
called an `inline_handler`. This new member indicates that there's a
handler which should be invoked inline. While this sits alongside the
existing `handler`, they are actually mutually exclusive. If an
`inline_handler` is specified then the `handler` is ignored and it is
assumed that the command is intended to be handled inline. The signature
of the inline handler is different to the standard handler, and this is
why a new function pointer was added rather than a simple flag. Addition of
this parameter meant that the basic command structure changed, and that
obviously affects all of the extensions and their respective commands.
This changeset therefore updates each of those command declarations so
that they use the new macros that hide this detail.

Other things to be mindful of:

* This version of the code reads the command's `method` prior to invoking
  any other function, and after that the command itself is passed around to
  the threaded or non-threaded routes for invocation. An extra thread
  parameter was included as as result, and an overload for the
  `thread_create` function was added which supported this new parameter.
  This was named `thread_create3` because
  `thread_create_with_another_paramter` sounded a bit crap.
* The migration code, which originally had a `thread_kill` and an event
  wait once the new meterpreter session had been created, has been modified
  to not do any waiting at all. Instead it finishes execution as fast as
  possible and returns control to the server which should respond by
  shutting down in a clean way.
* Originally the code always attempted to call a command handler in the
  base command list and then, if found, would also call an "overload" in
  the extension commands list. From the investigation that I did, it
  appears that the overloaded methods did nothing in the base (they'd
  early out during invocation). As a result, the new way of doing things
  acts like a 'true' overload in that the extension commands are searched
  first, and if one is found this is the command that is executed. Any
  base commands with the same method name will not get executed. In the
  case where there is no extension command found, the base command list is
  then queried. If a command is found that command is instead invoked.
* The POSIX version still compiles cleanly, but I've never been able to
  build a version that runs on my machines. I'm not sure if there's a
  trick to getting POSIX builds to run, and if there is I don't know it.
  Whoever scrutinises this build should make sure that the POSIX version
  that they build can still run and (hopefully) exit cleanly.

I've added lots of documentation, but there's always room for improvement.

Hopefully this will fix the `*_tcp` side of Redmine 8438.

Bring on the feedback!
Land #33, Fix XP SP3 Railgun Crashes