Bug 497831 - Can't change the date of a transaction with certain locales

This patch fixes the issue for the cs_CZ locale.
Fix still more overflow problems.
Bug 722123 - Zero price entry added to price database on stock purchase

Ensure that a 0 price isn't written from the stock register.
Bug 721822 - GnuCash 2.6.0 loads data file much slower than 2.4.x

Profiling shows the main problem is checking the strings in the file for
valid XML and UTF-8. This does both in one pass, which cuts the time in
half, but it's still far slower than 2.4.x was.
Fix compilation errors.
Revert "Bug 721822 - GnuCash 2.6.0 loads data file much slower than 2.4.x"

This reverts commit 6c461b3e952fd642d0cd76d7b546776a123e1858.
Bug 721472 - Fix Reconcile description column.

This patch changes the decription column to allow long
text to be elipsizsed when column width is too narrow.
Also if the text is elipsized and the mouse is over
the text, a tooltip will appear with full text showing.
Bug 725131 - Adding Payments to Fancy Invoice
Bug 724753 - Saved Multicolumn Report Error
Whitespace cleanup
Improve function names and comments to reduce ambibuity
Some code refactoring to avoid duplication
Fix SX Editor not being able to change the Repeat type from "Until".

The way this is stored depends upon the SX End Date being invalid, but
xaccSchedXActionSetLastOccurDate() rejected invalid dates, so once a valid
date had been created, it was impossible to change, except to another valid
date.
Bug 723216 - Cannot change the accounting period using the pop-up calendar

Set the GncDateEditor's time property, to which the GncPreference is bound.
If the property isn't set in a way that emits the "notify" signal the binding
doesn't know that it should change its value.
Release GnuCash 2.6.2
Win32 build: Update aqbanking version numbers
Aqbanking: SEPA transfer improvements - fix origin labels and add possibility to edit sender's name.
Refactor state saving function out of widget destruction
Bug 725534 - Scheduled transactions columns widths not retrieved
Bug 721654 - Style sheet preference is not saved for a Preconfigured Report