moves checkstr to common.c
[ELF] is working so far just need to make File opening and reading...
Merge branch 'master' into elf

Conflicts:
	MatrixOS.iso
	bin/MatrixOS.bin
	isodir/MatrixOS.bin
	src/common.o
	src/elf.h
	src/elf_loader.c
	src/elf_loader.o
	src/kernel.o
	src/system/shell.o
cleaned up code