arm-chocolate-doom.xml: added chocolate-doom 2.0.0
doom-legacy.xml: added section headers, deb_downloader_unpacker.sh
gzdoom.xml: fix variable name of git tag variable
Updated jenkins configs for new Jenkins version
renamed arm-preflight and arm-busybox to cross-[busybox|preflight]
cross-busybox.xml: updated cross-busybox with PPC build setup
cross-preflight.xml: added preflight checks for 32-bit PPC