Make 'make inttest' run in parallel even outside CI

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "third_party/cctz"]
 	path = third_party/cctz
 	url = https://github.com/google/cctz
+[submodule "third_party/gtest-parallel"]
+	path = third_party/gtest-parallel
+	url = https://github.com/google/gtest-parallel

NOTICE

@@ -17,6 +17,7 @@ ZNC includes code from Selectize (http://brianreavis.github.io/selectize.js/), l
 ZNC includes modified code from CMakeFindFrameworks.cmake by Kitware, Inc., licensed under BSD License.
 ZNC includes modified code from TestLargeFiles.cmake, licensed under Boost Software License, Version 1.0.
 ZNC includes code from cctz (https://github.com/google/cctz), licensed under the Apache License 2.0.
+ZNC includes code from gtest-parallel (https://github.com/google/gtest-parallel), licensed under the Apache License 2.0.
 
 ZNC is developed by these people:
 

make-tarball.sh

@@ -45,6 +45,8 @@ mkdir -p --mode=0755 $TMPDIR/$ZNCDIR/third_party/Csocket
 cp -p third_party/Csocket/Csocket.cc third_party/Csocket/Csocket.h $TMPDIR/$ZNCDIR/third_party/Csocket/
 mkdir -p --mode=0755 $TMPDIR/$ZNCDIR/third_party/cctz
 cp -Rp third_party/cctz/src third_party/cctz/include third_party/cctz/LICENSE.txt $TMPDIR/$ZNCDIR/third_party/cctz/
+mkdir -p --mode=0755 $TMPDIR/$ZNCDIR/third_party/gtest-parallel
+cp -p third_party/gtest-parallel/LICENSE third_party/gtest-parallel/gtest-parallel third_party/gtest-parallel/gtest-parallel.py $TMPDIR/$ZNCDIR/third_party/gtest-parallel/
 (
 	cd $TMPDIR2
 	cmake $TMPDIR/$ZNCDIR -DWANT_PERL=yes -DWANT_PYTHON=yes

test/CMakeLists.txt

@@ -102,5 +102,6 @@ add_custom_target(inttest COMMAND
 	# znc-buildmod should use the correct compiler.
 	# https://bugs.gentoo.org/699258 is an example of how it can go wrong.
 	${CMAKE_COMMAND} -E env MAKEFLAGS= CXX=${CMAKE_CXX_COMPILER}
+	"${PROJECT_SOURCE_DIR}/third_party/gtest-parallel/gtest-parallel"
 	"${CMAKE_CURRENT_BINARY_DIR}/integration/inttest")
 add_dependencies(inttest inttest_bin)