value-semantics concepts

[Manu343726]

Create concepts to check value semantics operations of a type, i.e.:

• [x] default construction
• [x] construction from value of type U
• [x] copy construction
• [x] move construction
• [x] copy asignment
• [x] move assignment

Also create features to implement value semantics operations of a type, i.e.:

• [x] default construction
• [x] construction from value of type U
• [x] copy construction
• [x] move construction
• [x] copy asignment
• [x] move assignment

[Manu343726]

Closing, all tests passing https://travis-ci.org/Manu343726/siplasplas/builds/151667850