* Support freetype2

* Before call pkg_search_module() check it is available.

* If using libraries are unavailable, this module is shown in unavailable list.

* using ocv_define_modules() insted of target_link_libraries().

* Fix inner indentation in C++ namespaces

* Remove mImg from freetype2 and Create UserData class to refer in path drawing callbacks.

* to split interface and implementation details.
( and to avoid 3rd headers in public headers)

* PKG_CONFIG_FOUND is used instead of COMMAND okg_search_modules

* Update Document using Doxygen

* Add ocv_module_include_directories()

* Do no put pixels over image boundaries.

* Fix SIGSEGV (only valgrind) and missing text in top border line

* Fix trailing whitespace.

* Use Header File Macros

* Fix CMP0023 warning in cmake

* std::string to cv::String

* Fix trailing whitespace

* Change splitnumber from unsigned int to int to support python

* ocv_include_directories() should be define before ocv_define_module()

* Fix boundary problem in putTextBitmapBlend()

* Fix to draw an outline glyph which are on the boundary of image.

* Remove precomp.cpp

* Fix CMakeLists.txt to right order.

* Remove prototype definition of removed function.

* Add CV_Assert() where FreeType and Harfbuzz are called

* Add CV_Assert() to check InputOutputArray and line_type