qmake really lacks version comparing functions:
users either use ugly constructions to compare versions
by components, such as
greaterThan(QT_CLANG_MAJOR_VERSION, 3)|greaterThan(QT_CLANG_MINOR_VERSION, 4):
or even incorrectly compare versions as strings:
!lessThan(apple_clang_ver, "5.1")|!lessThan(reg_clang_ver, "3.4"):
Add test functions versionAtLeast and versionAtMost which use
QVersionNumber to compare version numbers by components.
Change-Id: I65e6b3c296d0301d544b7e38bf3d44f8d555c7fc
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>