Skip loading files if base directories are identical

This should prevent duplicate loading of files when PATH_DATA,
PATH_DEFAULT_USER, and PATH_DEFAULT_DATA are the same. This is the case
on Windows and Amiga systems.
Merge pull request #691 from dorkster/bugfixes

Skip loading files if base directories are identical
Chinese by lonsine
Merge pull request #85 from clintbellanger/master

merge from main project
Currency as a stackable item

This sets currency to a set id (I picked 10, as it doesn't conflict with
current flare-game data). There's still refactoring that can be done
where currency functionality was different from normal items, but this
works as-is.
Better summon limit checking

player unable to use summon power if limit is hit. spawning enemies also
respect the summon limit
Merge pull request #86 from clintbellanger/master

merge from main project
Move manager classes to shared game resources
Remove unnecessary references
remove unnecessary includes
Attempt to fix calcDirection()
Cleanup old currency-specific code in LootManager

This commit obsoletes the currency sfx and currency_range settings in
engine/loot.txt. Instead, currency loot now uses data from its item
definition.

This has the added bonus of being able to define quantity
ranges for other types of loot. For example, a single potion vs a bag of
potions.
Move currency_id setting to engine/misc.txt
Add backwards-compatible support for currency key in save files
Remove global PowerManager
MenuStatBar: deal with large numbers as stats.
MenuStatBar: deal with large numbers as stats.
Hero experience is an unsigned long integer.

It makes no sense to have negative experience, does it?
Also people gain lot of it, so have a very large upper bound, hence the
long data type.
Merge pull request #697 from stefanbeller/longintexperience

Hero experience is an unsigned long integer.
Merge pull request #696 from stefanbeller/menustatbar_large_number

MenuStatBar: deal with large numbers as stats.