Version 1.1

Next step for a small library.

• names of some functions in AbstractData (and related classes) were changed;
• container-specific functions (as insertRow(), removeRow(), operator<<()) were added to StringData and VariantData classes;
• use Pimpl idiom with all public classes;
• Reader and Writer now can use QTextCodecs;
• support for Qt 5.5;
• more tests.

v1.0

Exlude installation of gcc-4.7 in .travis.yml