tests for checkVersionRange
[BUGFIX] "rc" versions not compared correctly

TYPO3 version number "4.7.0rc1" was seen as equal to "4.7.0".
We now use version_compare(), which already has support for
alpha/beta/rc version numbers.

Fixes: #36592
fix ExtensionTestServiceTest
get rid of versionToInt()
Merge pull request #4 from netresearch/TYPO-59-2

Fix bug #36592: "rc" versions not compared correctly