Added SUBMODULE Catch

Added Tests
   + Two command line tests data2data to test more cases of conversion between MERL and ALTA and with/without filtering
   + C++ Tests using catch for the same cases

.gitmodules

 [submodule "external/tinyexr"]
 	path = external/tinyexr
 	url = https://github.com/syoyo/tinyexr.git
+[submodule "external/Catch"]
+	path = external/Catch
+	url = https://github.com/philsquared/Catch.git

SConstruct

@@ -190,6 +190,14 @@ def library_available(env, pkgspec='', lib='', header='',
   conf.Finish()
   return result
 
+def catch_available(env):
+  """Return True if Catch is available."""
+  env.AppendUnique(CPPPATH = '#external')
+  conf = Configure(env)
+  has_catch = conf.CheckCXXHeader('Catch/single_include/catch.hpp')
+  conf.Finish()
+  return has_catch
+
 def openexr_available(env):
    """Return True if OpenEXR is available."""
    env.AppendUnique(CPPPATH = '#external')
@@ -277,7 +285,7 @@ int main(int argc, char* argv[]) {
   return has_cxx11
 
 # Export these for use in SConscripts.
-Export('CheckPKG', 'library_available', 'openexr_available')
+Export('CheckPKG', 'library_available', 'openexr_available', 'catch_available')
 
 conf = Configure(env, custom_tests = { 'CheckOpenMP': CheckOpenMP,
                                        'CheckCXX11' : CheckCXX11 })

sources/tests/SConscript

@@ -4,9 +4,10 @@ from os.path import basename, splitext
 
 import obtain
 
-Import('env', 'ALTA_LIBS', 'openexr_available')
+Import('env', 'ALTA_LIBS', 'openexr_available', 'catch_available')
 env = env.Clone()
 
+have_catch = catch_available(env)
 have_openexr = openexr_available(env)
 conf = Configure(env)
 have_cppquickcheck = conf.CheckLibWithHeader('cppqc', 'cppqc.h', 'C++')
@@ -201,25 +202,6 @@ if 'python' in COMMAND_LINE_TARGETS:
    for test in PYTHON_TESTS:
       make_test_python(test)
 
-# Test Some basic conversion 
-cmd00 = make_command_test('data2data', ['--param RUSIN_TH_TD_PD', 
-                                        '--input', test_byproduct('gold-metallic-paint.binary'),
-                                        '--in-data', 'data_merl',
-                                        '--output', test_byproduct('gold-metallic-paint.alta'),
-                                        '--all-values'],
-                          'merl-to-alta-all-values')
-AlwaysBuild(cmd00)
-env.Alias('tests',cmd00)
-
-cmd01 = make_command_test('data2data', ['--input', test_byproduct('gold-metallic-paint.alta'),
-                                         '--output', test_byproduct('gold-metallic-paint_positive_only.alta'),
-                                         '--all-values', '--param RUSIN_TH_TD_PD', '--ymin [0.0, 0.0, 0.0]'],
-                          'alta-to-alta-positive-values-only')
-
-env.Depends(cmd01,cmd00)
-AlwaysBuild(cmd01)
-env.Alias('tests',cmd01)
-
 
 # Make sure commands from the tutorials actually work.
 
@@ -292,6 +274,41 @@ downloadKrylon = env.Command(test_output_directory + '/krylon_blue_RGB.astm',
 downloadGold.noclean   = True
 downloadKrylon.noclean = True
 
+
+# Test Some basic conversion from MERL to ALTA ... 
+cmd00 = make_command_test('data2data', ['--param RUSIN_TH_TD_PD', 
+                                        '--input', test_byproduct('gold-metallic-paint.binary'),
+                                        '--in-data', 'data_merl',
+                                        '--output', test_byproduct('gold-metallic-paint.alta'),
+                                        '--all-values'],
+                          'merl-to-alta-all-values')
+
+env.Depends(cmd00, downloadGold)
+AlwaysBuild(cmd00)
+env.Alias('tests',cmd00)
+
+# ... and from ALTA to ALTA using filtering
+cmd01 = make_command_test('data2data', ['--input', test_byproduct('gold-metallic-paint.alta'),
+                                         '--output', test_byproduct('gold-metallic-paint_positive_only.alta'),
+                                         '--all-values', '--param RUSIN_TH_TD_PD', '--ymin [0.0, 0.0, 0.0]'],
+                          'alta-to-alta-positive-values-only')
+
+env.Depends(cmd01,cmd00)
+AlwaysBuild(cmd01)
+env.Alias('tests',cmd01)
+
+# ADD C++ Test if the two previous tests have passed and if Catch submodule is available
+if have_catch:
+  CXX_CATCH_TESTS = ['core/conversion-catch-1.cpp']
+  env.AppendUnique(CPPPATH = ['#external/Catch/single_include/'])
+
+  for test in CXX_CATCH_TESTS:
+    make_cxx_test_alias(test)
+  #end_for_loop
+
+#end_if_have_catch
+
+
 if have_openexr:
   cmd5 = make_command_test('data2data',
                            ['--input',