wxCRT_StrtoullBase(), used by wxString::To[U]LongLong(), didn't handle leading zeroes nor leading 0x correctly: it never auto-detected base 8; didn't ignore the leading 0 even if base 8 was specified explicitly; didn't recognize "0X" prefix at all (only "0x"). Fix all these bugs and add test cases for parsing numbers in other bases to the unit tests. Closes #14596. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72408 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775