* massive changes inside includes, drop unused definitions
* rewrite some initialization methods to avoid additional
freeing/allocation
* drop some explicit destructors calls
* drop c++14 requirements since it is not used
* move from enum to enum classes
* more intuitive graph building in GI
* allow X-AW-Direction property works with graphs and bars
more intuinitve configuration interface in graphicalitem. Improve code
for the future references (in case if new color type will be added).
Change X-AW-*Color values to ones with prefixes (added autoconversion
from old-version api)
* translation update
* fix broken build with gcc (#87). The issue was reproduced only with
gcc build and has been resolved by just replacing C-like `isnan` to
`std::isnan`
