[z2044] Send SMSG_DEFENSE_MESSAGE, SMSG_ZONE_UNDER_ATTACK only to players outside of instances

Also remove team argument from SendDefenseMessage as all texts are sent to all teams, use seperate function to send zone attack message, cleanup some send message functions and remove deprecated send text functions

(based on commit 9a43710)

Signed-off-by: Nighoo <nighoo@overninethousand.de>

(based on commit [s1657] - 8c318ee)
[z2045] Fix a bug with SCRIPT_COMMAND_KILL_CREDIT

This bug can happen if a (group) kill credit is provided without involved creature.
Thanks to Atari for pointing!

(based on commit 0fe6964)

Signed-off-by: Nighoo <nighoo@overninethousand.de>

(based on commit [s1658] - ce70a47)
[z2046] Fix some unintended custom literals.

(based on commit 0013661)

(based on commit [s1659] - 7021d03)
[z2047] Improve some mangos_string texts and command help texts

This closes pull request #75

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

(based on commit 5d1a3d9)

(cleaned version of d7d94d7)

(based on commit [s1660] - 14f186b)
Merge branch 'master' into testing