Merge pull request #310 from tbm/712-713-costs

Change the definition of cost
For ledger-post-align-postings to run on xacts added with ledger-add
fix code coverage problem
Merge pull request #311 from tripun/code_coverage

fix code coverage problem
Improve ledger-report-redo buffer type checking.
Merge commit '689112d3c0ffeb895ad4d8b9f61b50c5f537f0ed'