Xcode project: set gcc version to Xcode default for wesnothd

This was already done and accidentally committed together with
d9659f69b4a7d5b2d8a2b1ef9acab08d291c885f for Wesnoth
Xcode project: enable strict compilation
campaigns: purge unnecessary "recognize" magic comments
Added flat english map labels to aid localization.
SotBE S10: slight change to a message

The original version only makes sense if the AIs are winning at the
time.  The new version works either way.
SotBE S10: have AIs target only Inarix, not all saurians

Also set target value for Inarix equal to that of Kapou’e.  Otherwise
it is pretty much impossible to save Inarix.
SotBE S10: decrease value of villages for AI sides
SotBE S10: don't give huge unannounced gold bonus to AIs at turn 8

Instead, give AIs all the gold from the beginning, but stop recruiting
after a little less than half of it is spent.  At turn 8, start
recruiting again with the remaining gold.
SotBE S10: adjust player's starting gold
scons: Pass -Qunused-arguments to clang to skip warnings about unused -I paths

Step 1/2 in making it possible to build in strict mode with clang 3.3
and scons here.
scons: Pass -Wno-parentheses-equality to clang for src/lua/ library objects

Step 2/2 in making it possible to build in strict mode with clang 3.3
and scons here.
New macros AI_SAVE_GOLD and AI_SAVE_GOLD_DEFAULT

… to make enabling gold saving for the AI simpler in a scenario now
that it is not the default any more.
SotBE S1: use new macro AI_SAVE_GOLD_DEFAULT
Adds -Wextra-semi to pedantic compilation.

Also fixes all warning messages.
resources: Delete tree, it's now split to a different repository
UtBS 12: Remove keys where values match default
UtBS 12: Remove num_keys_found variable
UtBS 12: unstore_unit is capable of relocating units
UtBS 12: Spawn bats on rainforest, not tropical forest

While there was some tropical forest on the map, most has been changed
to rainforest. This change ensures that the bats stay in the jungle
proper. Also, by eliminating tropical forest as an option, the bats
will never spawn in the trees in the southern part of the island.
UtBS 12: Get rid of overridden flag variant