Some minor changes:
* Removed some forgotten references to rAthena.
* Updated script_commands.txt for an upcoming script command modification by @shennetsind.
* Corrected a typo in is_upper script command example.
* Updated doc/sample/npc_test_skill.txt to reflect the type 3 flag.

Signed-off-by: jaBote <j@bot.e>
Merge branch 'master' of https://github.com/HerculesWS/Hercules
Merge branch 'master' of https://github.com/HerculesWS/Hercules
Merge pull request #23 from jaBote/master

Some minor changes.
I'll be committing a script.c change to reflect these documentation changes within the next few minutes.