protobuf: add support for AArch64 (ARMv8)

Update config.{sub,guess} to support aarch64. Style cleanups.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
xerces-c: move back to 2.8.0

GEANT4 and CMSSW should be fine with moving to Xerces-C 3.1.X, but
not MCDB-API. Developers of MCDB-API were asked to update their package.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
freetype: bump to 2.5.3; add dependency on libpng

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
root: add supprot for AArch64 (ARMv8), libjpg -> libjpeg-turbo

Replace libjpg with libjpeg-turbo. libjpg was replaced years ago with
backward compatible, optimized version: libjpeg-turbo.

Add support for aarch64 for ROOT, CINT, and Cintex. ROOT target is
called 'linuxarm64'.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
roofit: add support AArch64 (ARMv8)

Two patches adds support for 'linuxarm64' target for ROOT, CINT, and
Cintex.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
cmssw-tool-conf: disable non-working packages on AArch64 (ARMv8)

Disable:
- qt-toolfile
- pyqt-toolfile
- dmtcp-toolfile
- valgrind-toolfile
- gccxml-toolfile

Rename db4-toolfile to db6-toolfile.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>