convert tabs to spaces (my tab stops aren't set to 8, so tabs wreck

[Linas Vepstas]

Log Message:
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convert tabs to spaces (my tab stops aren't set to 8, so tabs wreck indentation)
Replace crummy list usage, when a for-each would have been enough.
(this improves performance, reduces em fragmentation)

Modified Files:
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    gnucash/src/register/ledger-core:
        gnc-ledger-display.c