Added initial struct cpu implementation.
Renamed structure segement_descriptor to segdesc.
Renamed associated enums.
Global descriptor table initialization.
Added Doxygen support.
        Generate documentation using 'make doc'.
Changed subtitle for structs on file page.
graphviz dot support in Doxyfile.
Doxygen: enabled extraction of statics functions.
Fixed Doxyfile.in.
        - added additional kernel directories
        - changed scanning file pattern to *.h
        - enabled macro preprocessing and expansion
Added __DEBUG__ to the list of predefined macros.
Properly formatted comments for Doxygen documentation generation.
Merge branch 'docs' into cpu_bootstrap
Merge branch 'cpu_bootstrap' into devel

Conflicts:
	arch/x86/krnl4/mmu/idtr.h
	arch/x86/krnl4/mmu/ldtr.h