Vle compilation on win32

Commits for win32:
- compilation of vle relies on depenecencies provided as dll (in contrast with thus provided by mxe)
- CPack script is modified to take into account the new compiling environment 
- some fixes for win32

This pullrequest is associated with the pull request for vle packages 

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The cmds used for vle compilation :  

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** Variable
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set VLE_BUILD_ENV=c:\natifvle
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** Downloads and pre install
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Download Boost  into %VLE_BUILD_ENV%           **** boost_1_53_0
Download vle sources into %VLE_BUILD_ENV%    **** dev
Install Mingw (default)                                           **** mingw-get-inst-20120426.exe
Install gtkmm (default)                                          **** gtkmm-win32-devel-2.22 .0-1.exe

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** Install packages from mingw
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mingw-get install libarchive

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** set local variables
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set PKG_CONFIG_PATH=c:\gtkmm\lib\pkgconfig;C:\MinGW\lib\pkgconfig
set boostversion=1_53
set builddir="%VLE_BUILD_ENV%\build"
set sourcedir="%VLE_BUILD_ENV%\vle"
set installdir="%VLE_BUILD_ENV%\install"
mkdir %builddir%\vle
mkdir %builddir%\boost
mkdir %installdir%\vle
mkdir %installdir%\boost
set BOOST_ROOT=%VLE_BUILD_ENV%\install\boost

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** Build Boost
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cd %VLE_BUILD_ENV%\boost_%boostversion%_0\
bootstrap gcc
bjam.exe --toolset=gcc  --build-dir=%builddir%\boost --prefix=%installdir%\boost --without-signals --without-graph_parallel --without-mpi --without-python --without-serialization --without-atomic  --without-math --without-wave variant=release threading=multi link=shared runtime-link=shared install

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** Build vle
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cd %builddir%\vle
cmake.exe -G "MinGW Makefiles" -DWITH_MPI=OFF -DWITH_GTKSOURCEVIEW=OFF -DWITH_DOXYGEN=ON -DCMAKE_INSTALL_PREFIX=%installdir%\vle -DCMAKE_BUILD_TYPE=RelWithDebInfo -DVLE_MINGW_PATH="c:\mingw" -DVLE_GTK_PATH="c:\gtkmm" -DVLE_BOOST_INCLUDE_PATH="%VLE_BUILD_ENV%\install\boost\include\boost-%boostversion%" -DVLE_BOOST_LIBRARIES_PATH="%VLE_BUILD_ENV%\install\boost\lib"   %sourcedir%

mingw32-make install

set PATH=%installdir%\vle\bin;%PATH%
mingw32-make test

cpack.exe -G NSIS