[GNC] survey: unifying the appearance in different options dialogs

[Di Mang]

Hello gnucash user,

​​
during a comparison of the english and german versions of GnuCash, I
​have ​
noticed that the dialog "Book Options" looks different
​ly​
in both languages:
* in english version this dialog has four tabs, which are arranged at the
top (horizontally)
* in the
​german version there are five tabs (one tab more for tax data), which are
arranged on the left side (verticaly).

To fix this different appearance in both language, I have increased the
global value MAX_TAB_COUNT from 4 to 5 (see my PR:
https://github.com/Gnucash/gnucash/pull/382). This should make the
appearance of the "Book Options" dialog the same in both languages.

As noted by the jralls, it is a global setting and this change also affects
the appearance of the other reports' option dialogs with 5 tabs.

​​
It affect
​s​
only
​the following reports - the appearance of the tabs will change from left
side to the top:
* reports/Transaction Report (5 tabs)
* reports/Reconciliation Report (5 tabs)
* reports/Assets & Liabilities/Balance sheet using eguile-gnc (5 tabs)
* reports/Assets & Liabilities/General Ledger (5 tabs)
* reports/Business/Receipt (5 tabs)
* reports/Income & Expense/Equity Statement (5 tabs)
* reports/Income & Expense/Income Statement (5 tabs)
* reports/Income & Expense/Income and GST Statement (5 tabs)
* reports/Income & Expense/Profit & Loss (5 tabs)

​​
The following reports have 6 tabs and will be
​​
not affected from this change - tabs appears
​ furthermore​
on the left side:
* reports/Business/Australian Tax Invoice (6 tabs)
* reports/Business/Tax Invoice (6 tabs)
* reports/Income & Expense/Trial Balance (6 tabs)

In my opinion, this change leads to a consistent look of option dialogs in
reports and other preference dialogs. If we increase MAX_TAB_COUNT to 6,
the remaining three reports (see above) will get the same look too.

What do you think about it? Does this change have any disadvantages?

--
​​
best regards,
dimang