Support.php: rewrote appendTypo3ParameterToArray() to use Typo3 Store instead...

Support.php: rewrote appendTypo3ParameterToArray() to use Typo3 Store instead of _GET Parameter. Moved randomAlphaNum() to Support.
Link.php: rewrote handling of ToolTip. Renamed doHtmlUrl() to doAnchor().
Utils.php: moved randomAlphaNum() to Support.
Store.php: rewrote fillStoreClient() to be more compatible with phpUnit-test environment. Removed randomAlphaNum() - duplicate in Support.
AnbstractBuildForm.php: rewrote deriveNewRecordUrlFromExistingSip() to use generic Support::appendTypo3ParameterToArray()
Coding.md: Notes for debuggging.