Do not leave global known techs set when AI tests how knowing some currently
unknown tech would affect it. This fixes a problem that World -range Tech requirements
were far too often considered to be satisfied. Supplied rulesets use such requirements
for wonder obsolescense.

Reported by many freeciv-web users

See bug #22402


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25758 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Effectively reverted patch #4972, allowing specialist names with special characters again.


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25759 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Made infracache to calculate value of extras, and not separately for roads and bases.

See patch #4968


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25760 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Made client seeking older configuration file to know what was the last minor version
for each major version of freeciv.

See patch #4747


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25761 a0f10bec-cc02-0410-94fc-a9cfff90b4cd