this pr also fixes the sdl2 makefile in e55bf112f24976b09e6466751ea4bf9062c60f04, which was previously non functional.
side note: while fixing the makefile i noticed that -Wall creates a lot of warnings, a cursory glance at some of these reveals some that strongly look like real bugs, please consider adding -Wall to your private builds and fixing the warnings.
this fixes https://github.com/XProger/OpenLara/issues/400 by adding a command line option (-d) to set the data directory.
this pr also fixes the sdl2 makefile in e55bf112f24976b09e6466751ea4bf9062c60f04, which was previously non functional.
side note: while fixing the makefile i noticed that -Wall creates a lot of warnings, a cursory glance at some of these reveals some that strongly look like real bugs, please consider adding -Wall to your private builds and fixing the warnings.