[Makefile.am] Unit tests are not built by default

o make check in top-level-directory doesn't build anything
o `make -C benchmarks/test check' does the trick now
[infra] Dependency on MathMore optional
[CreateProject,examples] Unclutter makefiles

o remove redundancies and unnecessary copy&paste relics
o fix makefile dependency rules: running make twice builds one once
o remove commented code