[base] Add functions and variables to print logs to a file.

* include/freetype/internal/ftdebug.h: Added dlg's header files.
(FT_LOG): New macro to redirect trace logs to dlg's API's whenever
`FT_LOGGING' is defined.
(ft_logging_init, ft_logging_deinit): New functions to handle
initialization and uninitialization of logging related variables.
(ft_log_handler): New function to handle logs of FreeType.

* src/base/ftdebug.c: Add necessary logging related variables.
(ft_logging_init, ft_logging_deinit, ft_log_handler): Add function
definitions.

* src/base/ftinit.c (FT_Init_FreeType) [FT_LOGGING]: Call
`ft_logging_init`.
(FT_Done_FreeType) [FT_LOGGING]: Call `ft_logging_deinit`.

* src/base/ftobjs.c (FT_New_Library): Call `ft_debug_init` only if
`FT_LOGGING` is not defined.
5 files changed