This is an API change, but it seems better than having additional
colour-supporting variants and trying to avoid duplicated code.
I stopped short of changing showAmount, so cshowAmount still exists.
Renamed: writeValidJournal -> writeJournalTextIfValidAndChanged
Added comments clarifying line ending behaviour of:
add, import, appendToJournalFileOrStdout, readFilePortably,
writeFileWithBackupIfChanged, writeJournalTextIfValidAndChanged
Summary of current behaviour:
- hledger add and import commands will append with (at least some)
unix line endings, possibly causing the file to have mixed line
endings
- hledger-web edit and upload forms will write the file with
the current system's native line endings, ie changing all
line endings if the file previously used foreign line endings.