(svn r13688) [0.6] -Backport from trunk:
- Fix: If the first bridge can not be build for a given length, then none of the other bridges can. Effectively meaning that if someone replaces the first bridge with a bridge that can be only 3 tiles longs then only other bridges that can be 3 tiles long will be buildable, but only if they are 3 tiles long [FS#2100] (r13611)
- Fix: [OSX] 10.5 failed to switch to fullscreen (r13584)
- Fix: Properly count number of non-north housetiles [FS#2083] (r13518)
- Fix: Drawing of zoomed out partial sprites could cause deadlocks or crashes (r13502)