include glpk and rewrite makefiles

rcpp makefiles not required, changed behaviour in recent versions of the
package
cleanup and configure script for glpk, borrowed from rglpk-package
implementation of csp-algorithm (salazar and fischetti) in c++ which
will replace the r-based algorithm in future versions of the package
fix bug with packageVersion() if utils is not exported explicitely
allow to use the c++ implementation of the csp-algorithm for "OPT" and
"HITAS"

add some necessary helper-functions and add option "useC" to protect
Table()-options...
remove file
secondary cell suppression algorithm in c++
fix compiler warnings
update .gitignore
remove from git
remove makevars, not required due to changes in rcpp
fix bug with generic (V1...Vn) names of keys
redirect output to R-console and not to stdout (using Rprintf instead of
printf)
fix compiler warnings
do not use c-implementation of csp as default
bump to 0.11.0
Merge pull request #2 from bernhard-da/glpk

Glpk