Briefly increase the crosshair size when picking up a bonus.

The NewWolf source included commented-out code to draw a crosshair.
This code referred to a function and a texture definition that do not
exist, but it was evident that the size of the crosshair was intended
to briefly increase when picking up a bonus.

This commit adds a similar feature to the crosshair code added in
NewWolfLives and removes the commented-out code.  The magnitude of the
increase in crosshair size can be controlled by the
"crosshair_bonus_scale" cvar.

It is hoped that the result would be approved by DarkOne.
Use CMake for generation of Microsoft Visual Studio solution/project files.

To make it easier to control build flags, and to potentially support
other versions of Visual Studio, other compilers and other platforms
in the future, this commit replaces the Visual Studio solution/project
files with a CMakeLists.txt file that can be used to generate them.
README.md is updated to describe how this generation is performed.

The CMakeLists.txt should introduce minimal changes to the source file
lists presented in the Visual Studio IDE and to the build flags used.
The most significant change is that the "Release" configuration is
replaced with "RelWithDebInfo", which is CMake's standard name for an
optimised release build with debugging information, which is what the
old "Release" configuration was.

Output directories are also quite different from those created by
newwolf.vcproj - they are the CMake defaults now - as putting the
executables in an "exe" directory outside of the rest of the build
area is not a good idea: it breaks the ability to have multiple build
directories (e.g. for different versions of Visual Studio) with one
source tree/working copy.  Mappings from old to new paths:
exe/NewWolfLives_d.exe -> <build directory>/debug/NewWolfLives_d.exe
exe/NewWolfLives.exe -> <build directory>/relwithdebinfo/NewWolfLives.exe
prj_vs80/Debug/*.obj -> <build directory>NewWolfLives.dir/Debug/*.obj
prj_vs80/Release/*.obj -> <build directory>NewWolfLives.dir/RelWithDebInfo/*.obj

Notes on some of the settings in newwolf.vcproj that are not included
in CMakeLists.txt:
* MinimalRebuild="true": this is documented as only affecting C++, so
  is not relevant
* TargetMachine="1": this setting forces X86, but the default setting,
  which is to automatically detect the target, appears to work
  properly, at least when run on 32-bit Windows.  It may be necessary
  to use a CMake setting to control the target platform if builds are
  performed on 64-bit Windows.
* @todo comments are included for settings that are missing compared
  to newwolf.vcproj but may be added in the future.

Note that the "OldHeaders" filter/group shown in the IDE is now
clearly marked as "(still used)" to address a comment in the WolfGL3D
sources pointing out that this was confusing.
Remove resource editor .aps file from version control.

This is a binary version of the .rc file that Visual Studio's resource
editor keeps in sync with it, so there is no need to store it in
version control.
Add support for building with Visual C++ 2005 Express Edition.

The project could not previously be built using the Express Edition
because the .rc (resource script) file #includes afxres.h which is
part of ATL/MFC and hence not included in the Express Edition.  This
fix provides a stub implementation of that header file, which will be
used regardless of which edition of Visual C++ is used, and enables
the build to complete.  Note that the Express Edition does not provide
a resource editor for editing the .rc file, but it has already been
hand-edited and, as noted in a @todo in CMakeLists.txt, may have parts
automatically generated in the future.
Add support for Visual C++ 2008 and 2010, including Express Editions.

As it was found that the code can be built and run with Microsoft
Visual C++ 2008, Visual C++ 2008 Express Edition and Visual C++ 2010
Express Edition, this commit relaxes the version check in
CMakeLists.txt and updates the details on supported environments in
README.md.

A note is also added to CMakeLists.txt regarding a compiler option
that was recommended in a @todo comment but is deprecated in Visual
C++ 2008.  The 2010 documentation has not yet been checked to
determine if any other changes should be made to CMakeLists.txt.
Build instructions: correct CMake examples to include correct old dir name.

The instructions in README.md for running CMake included examples
referring to creating project/solution files in the directory that
they used to be stored in, but these examples didn't spell the old
directory name properly.  This commit fixes the directory name.