calls to range give ambiguity errors

fixes the following build problem in Fedora 19
using: boost-1.53.0-14.fc19.x86_64
using: gcc (GCC) 4.8.2 20131212 (Red Hat 4.8.2-7)

---snip--->
cpp_code/src/utils.cpp: In function
    ‘void copy_column(MatrixD, int, MatrixD&, int)’:
cpp_code/src/utils.cpp:350:16:
    error: reference to ‘range’ is ambiguous
    project(toM, range(0, num_rows), range(to_col, to_col+1)) = \
                ^
In file included
    from /usr/include/boost/numeric/ublas/detail/config.hpp:286:0,
    from /usr/include/boost/numeric/ublas/exception.hpp:25,
    from /usr/include/boost/numeric/ublas/storage.hpp:25,
    from /usr/include/boost/numeric/ublas/vector.hpp:19,
    from /usr/include/boost/numeric/ublas/matrix.hpp:16,
    from cpp_code/include/CrossCat/utils.h:33,
    from cpp_code/src/utils.cpp:20:
/usr/include/boost/numeric/ublas/fwd.hpp:33:27: note: candidates are:
    typedef class boost::numeric::ublas::basic_range<>
    boost::numeric::ublas::range typedef basic_range<> range;
                                                       ^
<---snip---
missing comma
don't assume the file is in a known place. it isn't always.
fix broken docs target in Makefile
z matrix plotting has broken variable name

Also don't leave a broken dangling plot window around. 
We're saving to a file, so clean up the screen.
Merge pull request #22 from fiendish/master

fix install