refactoring: reduce number of prepared statements
refactoring: reduce number of prepared statements

* for less memory usage
lewurm/cgeo,auricgoldfinger/cgeo,kumy/cgeo,schwabe/cgeo,madankb/cgeo,samueltardieu/cgeo,pstorch/cgeo,yummy222/cgeo,xiaoyanit/cgeo,brok85/cgeo,Huertix/cgeo,KublaikhanGeek/cgeo,auricgoldfinger/cgeo,Bananeweizen/cgeo,tobiasge/cgeo,pstorch/cgeo,SammysHP/cgeo,yummy222/cgeo,marco-dev/c-geo-opensource,samueltardieu/cgeo,cgeo/cgeo,cgeo/cgeo,samueltardieu/cgeo,Huertix/cgeo,xiaoyanit/cgeo,vishwakulkarni/cgeo,madankb/cgeo,auricgoldfinger/cgeo,kumy/cgeo,matej116/cgeo,rsudev/c-geo-opensource,superspindel/cgeo,ThibaultR/cgeo,KublaikhanGeek/cgeo,SammysHP/cgeo,xiaoyanit/cgeo,mucek4/cgeo,vishwakulkarni/cgeo,rsudev/c-geo-opensource,tobiasge/cgeo,schwabe/cgeo,madankb/cgeo,yummy222/cgeo,vishwakulkarni/cgeo,Bananeweizen/cgeo,mucek4/cgeo,matej116/cgeo,marco-dev/c-geo-opensource,superspindel/cgeo,cgeo/cgeo,Bananeweizen/cgeo,schwabe/cgeo,mucek4/cgeo,superspindel/cgeo,SammysHP/cgeo,kumy/cgeo,S-Bartfast/cgeo,rsudev/c-geo-opensource,S-Bartfast/cgeo,pstorch/cgeo,S-Bartfast/cgeo,schwabe/cgeo,brok85/cgeo,cgeo/cgeo,marco-dev/c-geo-opensource,Huertix/cgeo,lewurm/cgeo,matej116/cgeo,KublaikhanGeek/cgeo,ThibaultR/cgeo,ThibaultR/cgeo,lewurm/cgeo,tobiasge/cgeo,brok85/cgeo