Cleaned up item drop logic.

* Replaced bad exception logic with C-style error returns in ItemManager
* Removed unnecessary instances of objects being passed by value
* Fixed whitespace problems
* Added new config options to the default config.ini
* Updated tabledata reference

config.ini

@@ -38,6 +38,8 @@ xdtdata=tdata/xdt.json
 mobdata=tdata/mobs.json
 # path json
 pathdata=tdata/paths.json
+# drop json
+dropdata=tdata/drops.json
 # gruntwork output (this is what you submit)
 gruntwork=tdata/gruntwork.json
 
@@ -49,6 +51,15 @@ gruntwork=tdata/gruntwork.json
 # any number higher than 50 will disable commands
 accountlevel=1
 
+# should mobs drop event crates?
+# 0 = no event
+# 1 = Knishmas
+# 2 = Halloween
+# 3 = Easter
+eventmode=0
+# percent chance of an event crate dropping each kill
+eventcratechance=10
+
 # spawn coordinates (Z is height)
 # the supplied defaults are at Sector V (future)
 spawnx=632032