data-package-build: fix permissions; download empty files

- Set directories on 0755 and files on 0644.
- cURL does not download empty files thus touch files before
  downloading.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
dmtcp: new external at (2.0-2060, pre 2.0)

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
xrootd: bump version to 3.3.3; add private headers to incl. path

Second attempt to enable xrootd 3.3.3 (final). CMSSW depends on
private implementation details in xrootd, thus add ./include/
xrootd/private to incl. path.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
mpfr-static: new external at 3.0.1 (with PIC)

MPFR 3.0.1 static library with PIC enabled. Intended to be used
as BuildRequires for CGAL.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
gmp-static: new external at 5.0.2 (with PIC)

GMP 5.0.2 static library with PIC enabled. Inteded to be used as
BuildRequires.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
cgal,cgal-toolfile,cmssw-tool-conf: use static GMP and MPFR

- Add zlib and boost_system to cgal-toolfile (SCRAM).
- Rename CGAL to cgal.
- Use gmp-static and mpfr-static packages. Thus eliminating having
  two libraries in LD_LIBRARY_PATH and library search path for linking.
- Tested on Yue Shi Lai <ylai@mit.edu> example on CMSSW_7_0_X_2013-07-
  25-1400. Compiled without issues.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
cgal: fix typo in tarball name

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Merge pull request #147 from davidlt/July30-70X-external-update

[CMSSW_7_0_X] DMTCP; CGAL; gmp-static; mpfr-static; fix data package permissions