lazutils: made codepage conversion 1250 to UTF8 and back to 1250 lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42011 4005530d-fff6-0310-9dd1-cebe43e6787f
tests: added test if CP1250-UTF8-CP1250 is lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42012 4005530d-fff6-0310-9dd1-cebe43e6787f
lazutils: made codepage conversion 1251 to UTF8 and back to 1251 lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42013 4005530d-fff6-0310-9dd1-cebe43e6787f
tests: added test if CP1251-UTF8-CP1251 is lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42014 4005530d-fff6-0310-9dd1-cebe43e6787f
tests: added test if CP1252-UTF8-CP1252 is lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42015 4005530d-fff6-0310-9dd1-cebe43e6787f
lazutils: made codepage conversion 1252 to UTF8 and back to 1252 lossless

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42016 4005530d-fff6-0310-9dd1-cebe43e6787f