(svn r9543) -Fix [FS#691]: Split up STR_ENGINE_NOT_BUILDABLE into four strings so it can be
translated properly and remove "buildable", since it isn't actually a word.

(svn r9542) -Fix(FS# 712): When checking if a vehicle is on a given tile, and you are working on the ground tile, do not take aircrafts into account, as they do not pose any danger for the construction/destruction/conversion itself. Z stuff, in other words

(svn r9541) -Codechange: Safeguard the company-buying routines so that the buying player and the bought player need to be two different entities

(svn r9540) -Fix (r1): Bankrupt AIs no longer buy themselves (usage of wrong variable)

(svn r9533) -Fix [FS#274]: when a company is removed (either via auto-clean, bankrupt, or take over), sell all the shares he has first, then sell the shares all people have on this company, and then remove the company.

(svn r9532) -Fix (r8741) [FS#708]: Make errors when building drive through road stops more descriptive.

(svn r9531) -Fix (r8661) [FS#692]: The scroll settings were wrong for trains as only a part
of the window should be horizontally scrollable, not all of it. This lead to
wagons without an engine overflowing the window and not being able to scroll to
the end of a train if there was an engine attached.

(svn r9530) -Codechange: Replace a direct industry type access by a behaviour

(svn r9529) -Fix [FS#705]: when 2 clients joined together, the second asserted on the NewCompany command of the first

(svn r9528) -Fix r8610: don't try to modify non-existent widgets (many thanks to Bruce Perence, the libefence developer)