Merge pull request #804 from hpcugent/develop

release EasyBuild v1.10.0
gen_builddir: do not create unique dir if cleanoldbuild is true
Updated test for gen_builddir
Have fallback if 'cleanupoldbuild' is not set
Merge branch 'cleanupoldbuild' of github.com:wpoely86/easybuild-framework into cleanupoldbuild
add unit test to make sure cleaning up old build dir is default
Merge pull request #809 from wpoely86/cleanupoldbuild

gen_builddir: no unique dir if cleanoldbuild is set