Merge from tiOPF2: Minor fix for mediators that also use the ValueList property.

The problem was that we never set FListObject = nil when the ValueList
was freed. Thanks to Carlo Marona for supplying the patch.
Updates the XE & XE2 Core packages with the missing tiSemaphore unit.
Fixes TtiFieldCurrency.AsCurrencyString to take into account locale values.
tiFloatToCurrency never included currency symbol in error value.

If this function gave an error, the error value of 0.00 never contained
the currency symbol - like a normal answer would have produced.
tests: TtiObjectTestCase.FieldCurrency now takes locale currency symbol in account

Before it was hard-coded to the $ (dollar) symbol.
tests: TtiObjectTestCase.FieldDate now has a minor work-around to run

With the UK locale this test failed. We now simply set the ShortDateFormat
for that specific test, then restore it again afterwards. Date formats are
still work in progress in the test suite.
tests: minor tweak to allow test suite to work with locals for TtiFloatToCurrency

With recent changes tiFloatToCurrency now uses the locale currency symbol,
not the hard coded $ (dollar) symbol. The tests needed to adapt for it.
DataAndPropertyValid method can now handly property paths too.

Thanks to Carlo Marona for the suggestion.