Fixed solutions for week2

Whats new?
+ All tests seem to be passed
+ All solution stuff has been moved to separate namespaces
+ Removed wrong assignment operators
+ Fixed bunch of small issues 

Some comments for closed pull request https://github.com/marozau/cpp_craft_0314/pull/98:

Unfortunately, I didn't understand what "radeMsgSummary::value_type" means. 

"...you store seconds in uniq_seconds. Only one positive thing - it's easy to implement. But...
It's not an effective solution. It consumes too much memory and it's slow."  I know. Yeah, It was 2 a.m., now it's 2.40 a.m.  Only 2 thoughts in my brain: "..premature optimization is the root of all evil" and "time to sleep". :)

"it's better to define struct with clear variable names instead of pair with first and second fields." - yeah, maybe in third-week-solution.

"What is your code style?..." - I asked question about code style at first lesson - and obtained the answer: "it doesn't matter".  Therefore I just wrote the code without paying big attention to style.
I think, code style is something project-specific. If I want to contribute to boost, I'll definitely format all the code according to boost code style.