this allows global changes to how data is written with one change
currently, it only converts from big-endian to little-endian
in the future, this will allow an easy transition to writing 64-bit data
git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@4566 212acab6-be3b-0410-9dea-997c60f758d6
