added first version of userspace fork/kill support to new branch
Merge branch 'paging' into paging-fork

Conflicts:
	arch/x86/mm/page.c
fixed syntax errors and compiler warnings in new branch
Merge branch 'paging-fork' of https://github.com/stv0g/eduOS into stage6
add crosscompile prefix to environment variable GDB
fix wrong pointer check
get_current_stack set CR3 => required for a context switch