Fix price quotes after removal of yahoo-get-historical-quotes
calculate num-columns-required correctly

This fix, calculates num-columns-required correctly based on which columns are used/not-used/merged. Earlier code did not consider merged columns.

Effectively with this fix, when you print report, on average it saves 2-3 pages per 12-15 pages.
Additional changes to column calculations

- Add some comments to remember why this was done
- Fix one error in the code
Fix code that customizes parameters for specific gcc versions
to agree with the comments.
Ignore SIGTTOU while importing Python console class.

Importing it causes this signal to be sent and if GnuCash is running
in the background it hangs.
Merge branch 'maint'

  * Fix price quotes after removal of yahoo-get-historical-quotes
  * calculate num-columns-required in transaction report correctly
  * Additional changes to column calculations in transaction report
  * Fix configure.ac code that customizes parameters for specific gcc versions
  * Ignore SIGTTOU while importing Python console class.