Improve sidewalk-building logic.
Choose orientation (layout) for city buildings using a more sophisticated system
Fix loads of compilation errors in last commit.
MERGE (cherry-pick) Prissi's variant of my house clustering from standard.  CHANGE: Cluster factor is applied only as a multiplier, not as a divider; change default from 10 to 100.  ( ADD: (neroden) clustering of houses, set "cluster_factor" in cityrules.tab to about 10 times the typical distribution weight)

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6501 8aca7d54-2c30-db11-9de9-000461428c89

Conflicts:
	bauer/hausbauer.cc
	bauer/hausbauer.h
	besch/haus_besch.h
	simcity.cc
	simcity.h
	simutrans/history.txt
Remove indentation in prep for merge...
Relocate function in simcity.cc in preparation for merge.
MERGE: Merge prissi's changes to clustering code (except the ones which are wrong).  Merge branch 'prissi-cherrypick' into prettier-cities-2

Conflicts:
	simcity.cc
Rewrite code to prevent "boring cities" (to avoid rows of identical non-clustering buildings).
Fix thinko in previous commit.
Fix crash bug when cities build streets (missing null pointer check, whoops)
Comment out "unboring" rule for level 0 (new build) buildings; it may be causing trouble.
Merge branch 'ncn-devel' into prettier-cities-2
Add bridge_success_percentage option to cityrules.tab.  Also transfer cluster_factor for networked games.
Add comments in simcity.cc in prep for rewriting city growth.
Merge branch 'ncn-devel' into prettier-cities-2
Merge branch 'ncn-devel' into prettier-cities-2
Merge branch 'ncn-devel' into prettier-cities-2
Merge branch 'ncn-devel' into prettier-cities-2
Merge branch 'prettier-cities-2' of git://github.com/neroden/simutrans.git into 11.x