Use macros for uclass_index() and utype_class()

See patch #4934

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25551 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Really assert tech is in valid range

See patch #4937

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25552 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Consolidate server precalcs and cache population

See patch #4938

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25553 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Use const for more sorts of requirement checks

See patch #4939

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25554 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Allow moves to native roads from native terrains

Reported by Jacob Nevins <jtn>

See bug #22319

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25555 a0f10bec-cc02-0410-94fc-a9cfff90b4cd