Add a TestLoad setting to CTest that can be set via a new --test-load
command-line option, CTEST_TEST_LOAD variable, or TEST_LOAD option to
the ctest_test command. Teach cmCTestMultiProcessHandler to measure
the CPU load and avoid starting tests that may take more than the
spare load currently available. The expression
<current_load> + <test_processors> <= <max-load>
must be true to start a new test.
Co-Author: Zack Galbreath <zack.galbreath@kitware.com>
Betsy McPhail