(svn r9342) [0.5] -Backport from trunk (r8980, r9065, r9339):
- Fix: the industry list should also be (re)set when the number of industries is 0 (r8980)
- Fix: possible dereference of NULL pointer (r9065)
- Codechange: disable shares by default and increase the default maximum distance from edge for oil refineries (r9339)