[z1940] Rewrite and cleanup DB Script Engine

* Moved actual script processing code to ScriptMgr
* Unifed and improved log output. Now table-name is passed to each script execution
* Added the "buddy concept" to all commands (except the outdated direct field change commands):
Now all commands support to search a creature (or go for some commands) in a radius, with which to do some stuff.
See doc/script_commands.txt for more details and information

Attention DB Devs:
Current DB-Scripts are converted automatically as far as possible, but some old target selecting mechanics were not reasonable to do automated.
For such cases the command is marked with data_flags & 0x10 (==16), which will throw DB-Errors to track them down faster

Thanks to NeatElves and especially Grz3s for testing!

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>
Signed-off-by: Nighoo <nighoo@gmail.com>

(cleaned version of 6701840)

(based on commit [s1528] - a4636fe)