Small update, related to code generation; Warning removed in the string class.

git-svn-id: svn://svn.code.sf.net/p/acado/code/trunk@158 f4037fd0-e48f-4cc9-9f8e-e12ed3b76bf3
clang related warning removed...

git-svn-id: svn://svn.code.sf.net/p/acado/code/trunk@159 f4037fd0-e48f-4cc9-9f8e-e12ed3b76bf3
Bug fixes in CMake compiler options related to optimizations...

git-svn-id: svn://svn.code.sf.net/p/acado/code/trunk@160 f4037fd0-e48f-4cc9-9f8e-e12ed3b76bf3
Added -DLINUX to compiler options -- important for time measurements

git-svn-id: svn://svn.code.sf.net/p/acado/code/trunk@161 f4037fd0-e48f-4cc9-9f8e-e12ed3b76bf3