Fix 10 qt4tests test cases for fn:format-integer

[GuntherRademacher]

Here are some changes of fn:format-integer, which will

• consider an explicit radix only if an X or x mandatory-digit-sign is present in the primary format token
• prevent separators from appearing in the result before any digits
• handle format pictures containing X or x mandatory-digit-signs, when an explicit radix is present.

They will fix these tests from qt4tests:

• format-integer-030
• format-integer-40-001
• format-integer-40-002
• format-integer-40-008
• format-integer-40-009
• format-integer-40-010
• format-integer-40-013
• format-integer-40-016
• format-integer-40-014
• format-integer-40-015