modify sax::Converter::convertMeasure to use sal_Int64 instead of BigInt:
should be sufficient, since the largest number is SAL_INT32_MAX * 10^7.
remove duplicate methods from SvXMLUnitConverter:
convertMeasurePx, convertMeasure (static variants)
remove entirely duplicative class SvXMLExportHelper:
GetConversionFactor, GetUnitFromString, AddLength
change SvXMLUnitConverter interface from MapUnit to css::util::MeasureUnit.
change SvXMLExport constructor params from MapUnit to css::util::MeasureUnit.
rename some methods to turn compiler into merge conflict detector :)
