Remove all OMP_ON guarded fragments

`OMP_ON` macro is not defined anywhere in the project. Some cleanups
were already done on 3 Oct 2013, e.g.,:

    91c67db2dc42797913c89684910bbc50665c5a21

The patch removes the rest of them.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Remove -Xcompiler option when compiling with GCC (OpenMP)

The patch removes unknown `-Xcompiler` option for GCC when compiling for
OpenMP mode:

    unrecognized command line option '-Xcompiler'

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Add missing <climits> header for INT_MAX constant

The patch adds a missing <climits> header needed for `INT_MAX` constant.

    MixFit.cc: In function 'void makeFullFitVariables()':
    MixFit.cc:905:48: error: 'INT_MAX' was not declared in this scope

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Resolve deprecated conversion from string constant to 'char*' warnings

The patch resolves the following warnings:

    MixFit.cc: In function 'GooPdf* makeOverallSignal()':
    MixFit.cc:2069:59: warning: deprecated conversion from string
    constant to 'char*' [-Wwrite-strings]
       loadDataFile("./dataFiles/efficiency_flat.txt", &effdata);
                                                               ^
    MixFit.cc: In function 'void runGeneratedMCFit(char*, int, double)':
    MixFit.cc:2283:61: warning: deprecated conversion from string
    constant to 'char*' [-Wwrite-strings]
       loadDataFile("./dataFiles/efficiency_gen.txt", &effdata, 1);
                                                                 ^
    MixFit.cc: In function 'void runEfficiencyFit(int)':
    MixFit.cc:3594:70: warning: deprecated conversion from string
    constant to 'char*' [-Wwrite-strings]
       if (3 == which)
    loadDataFile("./dataFiles/efficiency_bkg3_flat.txt");
                                                                          ^
    MixFit.cc:3595:54: warning: deprecated conversion from string
    constant to 'char*' [-Wwrite-strings]
       else loadDataFile("./dataFiles/efficiency_flat.txt");

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Use `root-config` to find ROOT incl and lib directories (incl. libs)

ROOT5 by default install headers in (../include/root) and libraries in
(../lib/root). This can be changed by user when compiling ROOT5. Use
`root-config` (comes with ROOT5) to find include and libraries
directories. Also this provides a lit of ROOT5 libraries for linking
stage.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Do not link to cudart if compilig for OpenMP

CUDA run-time is not needed when compiling for OpenMP mode and causes
issues:

    x86_64-redhat-linux-gnu/bin/ld: cannot find -lcudart

The patch removes it from OpenMP mode.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Use THRUST_DEVICE_SYSTEM instead of THRUST_DEVICE_BACKEND

Thrust 1.7 deprecates THRUST_DEVICE_BACKEND in place of
THRUST_DEVICE_SYSTEM. THRUST_DEVICE_SYSTEM is used in the main GooFit
Makefile. Change it in pipipi0DPFit example to be consistent and remove
warnings from Thrust.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Merge pull request #17 from davidlt/misc-clean-ups

Misc clean ups for GooFit and pipipi0DPFit example