x64: further adjustments to X64VirtualAddressSpace::clone and X64VirtualAddressSpace::revertToKernelAddressSpace
build: add -fno-omit-frame-pointer to x86_64 default compile flags.
x86_common: make bitmap for PhysicalMemoryManager debugging use a preprocessor define (USE_BITMAP)
build: use a copy of stage2_eltorito for ISO builds rather than the in-repo one (as mkisofs modifies it).
process: disable interrupts without using a local Spinlock in Process destructor
debugger: in MappingCommand, only switch to the kernel address space if necessary.
vfs: don't premap AnonymousMemoryMaps (as this then happens in ::clone and such, where ::clone is only meant to transfer metadata).
testsuite: new application 'testsuite', for running various system tests (that do not exist yet).
posix: check event state when submitting a threadException to the running thread.
vfs: added methods to MemoryMappedObject and MemoryMapManager to modify access permissions on mappings.
posix: added mprotect(2)
testsuite: provide a 'fail' function that tests can call to immediately terminate (including from signal handlers).
testsuite: added mprotect(2) tests