Decouple externally tvector and history
Inline a lot of history class
Semantic change: do a full copy instead of a partial copy for history change

The code do a full copy aka new object could be modified independantly of copied object of history.
No change are expected because this method is not compiled in*

* exactly this method is compiled in but the callee functions are not called. So dead code.
Convert history to std::vector

std::vector is a storage class of element. History does not need mathematical vector
Avoid leak using std::shared_ptr

Avoid leak using shared_ptr
Test sweep simulation
Add const decoration to environment
Remove unused characteristic.cpp
Remove unused operatingpoint.cpp
Delete pair.cpp
use std::string in property
Use std::string for text concatenation in strlist
Simplify handling of string
Use std::string for variable name

Put const identifier in order to correct compile error
Remove txt member of variable
Constantify some variable
Use forward object to speed up compilation
Remove ptxt from object

Win a pointer per object
Constantify object

Help compiler and create better code
Convert property to std::string for name

Pass std::string and return std::string