stat structure (from <sys/stat.h>) is conditionally defined
to have different layout and size depending on the defined macros.
The correct macro is defined in my_config.h, which means it MUST be
included first (or, at least before <features.h> - so, practically,
before including any system headers).
- Fixed compiler errors
- Modified Makefiles to be part of plugin directory
- Some minor changes in database.cpp to use the new MariaDB handler interface
