Fixes #46

The implementation for std::string (which is a base class of
TNL::String) is perfectly sufficient.

Tomáš Oberhuber authored 6 years ago and Tomáš Oberhuber committed 5 years ago

Splitting the String examples.
Adding String enum 'SplitSkipEmpty' for the method split.

Explicit is better than implicit: https://www.python.org/dev/peps/pep-0020/

[ci skip]

New way of (de)serialization of objects into TNL::File using operator<< and operator>> (starting with string)

This is nicer and safer (thanks to exceptions) than save/load functions.
Moreover, it breaks the last cyclic dependency between TNL classes.

Return values are nicer than modifiable parameters. This also avoids the
circular dependency between TNL::String and List.

fixes #18