Dealt with some g++ 4.8, c++11 compilation issues
Fixed some gcc 4.8 issues in C++11 mode with index_pair and index_triple
Merge pull request #2 from uBLAS/develop

merging massive pull request from Nasos,
Some test fixes
Minor changes for c++11 compilation
Minor changes in concepts.hpp to avoid warning with clang
Reactivated test_triangular. There is probably a problem with boost timer and clang c++98, because of the C99 standard about empty macros
Merge remote-tracking branch 'ublas_upstream/develop' into develop