LuxRender Static Compilation Environment

This collection of scripts is intended for automatic creation of build
environment and Lux compilation with statically linked dependency libs.

 - build
   The main routine.
 - build-64-sse2
   Wrapper script for compiling on the most common platforms.
 - distfiles
   Directory for the downloaded dependencies sources.
 - distfiles/files
   Dependencies manifest.
 - utils
   Directory containing a few helper scripts.

Some dependencies aren't addressed by the script, and must be resolved
by the user prior to compilation. Among them are:
 - Python 3 (3.4 for use with Blender 2.70 and above)
 - OpenGL Graphics Library (MESA)
 - OpenGL Extension Wrangler Library (GLEW)
 - OpenCL library and header files (if you need OpenCL support)

Running build script for the first time will download dependencies
sources into the distfiles dir, taking about 300 MB of disk space.
Complete environment requires additional 300-400 MB for each architecture.
You also need enough space in your tmp directory to allow unpacking and
compilation of the largest deps -- Boost and Qt.

When build script is envoked, it will check for the main prereqisites,
try to figure out what's missing, and prepare the compilation environment
below the 'root' directory -- the dir where the script resides (although
paths are configurable in build-* wrapper scripts).

The easies way to start compilation is by using the wrapper scripts
which have all the variables preconfigured for the most common platforms.
Here is how you can do this:

 1. Unpack LuxRender sources into the subdirectory below 'root' directory
    (where scripts are located). The subdir with Lux sources may have
    any name, however if it ends with '-opencl' then OpenCL-enabled
    version is compiled; if it contains 'pyluxcore' then only pyluxcore
    target will be compiled; if the name doesn't have this extension then
    Lux is compiled without OpenCL support.
 2. Unpack LuxRays sources into the 'luxrays' subdirectory below Lux
    sources directory.
 3. Run the wrapper script passing it the name of LuxRender sources dir
    and optionally the stage number:
    ./build-64-sse2 <lux sources> [stage]
    To see a list of valid stage numbers run the script without any
    parameters. Specifying a stage allows you to recompile any deps if
    needed (however in such a case it's usually better to delete
    target-* dir altogether and start from scratch).
    If stage number is omitted the script will continue from where it
    was previously terminated, i.e. resume compilation of unfinished
    deps, or begin compiling LuxRays and LuxRender if all dependencies
    are in place.
 4. Once the compilation is complete, Lux binaries and shared libs are
    packed in tar.bz2 archive and saved below the platform-specific
    'target' subdirectory.

The compilation environment supports Clang for compiling both LuxRender
dependencies and LuxRender itself. In order to enable it, create an empty
file named "use_clang" in compilation enviroment root directory. Make sure
you have the following components properly installed in your system:
 - Clang compiler (with executable under PATH env var)
 - libomp (OMP library for Clang)
 - LLVM with Clang support and Gold linker

If you have any questions and suggestions regarding these tools, leave
them in