Merge pull request #1 from kl7107/master

Improved error output for build-tools scripts
Merge pull request #2 from kl7107/master

Added prerequisites check when building the rtems toolchain
Made bootrom.elf a standalone target in the marin/nexys3 makefile
Pull QEMU from qemu-moxie staging repository
Don't include ELF header in resulting binary
Add memory map document
Fix some comments
Fix enabling of interrupts
Added qemu_marin_boot.S helper startup code
Added comment to download script with Ubuntu package sources for tools
Merge branch 'master' of https://github.com/atgreen/moxie-cores