* Add test for reporter output.

* setup err_stream tests

* Fix warnings in tests

* whitespace

* Fix build errors caused by super pedantic compilers

* Pass streams by pointer not non-const reference

Merge branch 'update_complexity' of git://github.com/ismaelJimenez/benchmark into ismaelJimenez-update_complexity

Force DoNotOptimize operand to memory for both gcc and clang

Add checks that <Resume|Pause>Timing functions are not called outside of the KeepRunning() loop. Fixes #204