replace calls to 'uname -p' by 'uname -m'

Using 'uname -p' is broken on some distros (does not work in
Gentoo, Arch, maybe others). The recommended way to fetch the
arch is by using 'uname -m'.
limit the number of concurrent jobs to 8

Having too many concurrent jobs might hang the build process, it's
safer to limit the ammount to 8. The magic number 8 comes from the
build process for the OpenJDK PowerPC/AIX Port (JEP 175).
add build support for ppc64
update OBF_BASE_ARCH to include ppc64 arch
fix openjdk build for powerpc port

Add missing JDK7u environment variables and JDK8 configure flag.
export ant_home

Since Ant is automatically fetched and added to PATH by the script
it's best to export ANT_HOME as well.
add ppc64 to fastdebug build

Include detection of PPC64 arch, set BUILD_PROFILE, and add
an EXTRA_FLAGS for additional (but exclusive) configure flags.
remove OPENJDK=true build variable

The OpenJDK build automatically detects when no closed source
directories exist so there's no need to set OPENJDK.
Merge pull request #14 from tdaitx/master

Add support for building OpenJDK on PPC64 (from the PowerPC/AIX Port - JEP175)