Added ReplaceNewlineWithBrTagInHtml property to MailTarget

Added ReplaceNewlineWithBrTagInHtml property to MailTarget
which defaults to false
Fix build error for Windows Phone
Remove namespace
Fix build error
Fix build error
Fix build error in CF
Fix build error
Merge branch 'master' of git://github.com/slolife/NLog into slolife-master
Fix line ending
Added test for no ReplaceNewlinesWithBr
Fixed failing test