Fix #1156, delete some unused functions

#1156 seems not to be moved to github's issue tracker. 

For other functions that are unused but can't be deleted (their deletion can break abstractness of some classes) I recommend passing -Wl,--gc-sections to linker and -ffunction-sections -fdata-sections to compiler settings. This will eliminate unused functions whilst compiling. By default, it's not done with -O2 or -O3. For further info please have a look at http://gcc.gnu.org/onlinedocs/gnat_ugn_unw/Compilation-options.html