[C] Call PotionSplashEvent even for no effects. Fixes BUKKIT-3618

##### The Issue:
When there are no effects applicable, as in the case of a Mundane splash potion, PotionSplashEvent would not be called.  Only ProjectileHitEvent would be called and it's not easy to determine the targets that would be hit by the splash area of effect nor is it a consistent expectation for developing plugins with potions that want to apply their own custom effects using potions like Mundane splash potions.

##### Justification for this PR:
Calling PotionSplashEvent will leverage the default code for determining affected targets and create a consistent interaction with potions for plugin authors.

##### PR Breakdown:
This commit simply allows the logic for determining affected targets to be executed even if no effects are found on a potion when it splashes.
 
##### Testing Results and Materials:
[Test Plugin](https://github.com/EdGruberman/bukkit-test/blob/master/BUKKIT-3618/dist/BUKKIT-3618.jar?raw=true)  |  [Test Source](https://github.com/EdGruberman/bukkit-test/blob/master/BUKKIT-3618/src/edgruberman/bukkit/bukkit_3618/Main.java)

Log output which demonstrates the event was fired using both potions with and without effects and none or some affected entities as I through potions at helpless sheep and pigs. The sheep didn't mind the mundane potions, but the pig gave me a dirty look for the poison potion.
```2013-03-28 10:03:47 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 24576, effects: 0, affected: 2
2013-03-28 10:03:49 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 24576, effects: 0, affected: 1
2013-03-28 10:03:52 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 24576, effects: 0, affected: 1
2013-03-28 10:03:55 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 24576, effects: 0, affected: 0
2013-03-28 10:04:10 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 16385, effects: 1, affected: 0
2013-03-28 10:04:19 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 16385, effects: 1, affected: 2
2013-03-28 10:04:22 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 16385, effects: 1, affected: 1
2013-03-28 10:04:30 [INFO] [BUKKIT-3618] PotionSplashEvent; durability: 16452, effects: 1, affected: 1```

##### Relevant PR(s): 
None
 
##### JIRA Ticket: 
[BUKKIT-3618](https://bukkit.atlassian.net/browse/BUKKIT-3618)

##### Pull Request Check List:

**General:**

- [x] Fits Bukkit's Goals
- [x] Leaky Ticket Ready
- [x] Code Meets Requirements
- [x] Code is Documented
- [x] Code Addresses Leaky Ticket
- [x] Followed Pull Request Format
- [x] Tested Code
- [x] Included Test Material and Source
- [x] Follows Minimal Diff Policy
- [x] Uses Proper CraftBukkit Comments