Core/Group: Add sanity checks to CMSG_LOOT_METHOD's handler

If lootMethod or lootThreshold is invalid, portrait menus become unusable to the entire raid.
Core/Group: Fix exploit

The master looter should be in the group.
Core/Group: Any party member may mark targets (this does not apply to raid groups)

Also ensure that the targeted player is not hostile.
Merge pull request #11584 from Dehravor/group

Group related fixes
DB/Items: Fix some startup errors

By Fateswhisper, updates #11587
DB/Quest: Fix 3 quests texts

By MrSmite, closes #11585, closes #11582
Core/MMAPS: Fix invisible wall issue in MMAPS.

Fix invisible wall issues in MMAPS caused by tile connections not being extracted correctly.
This reverts aa645683b8b25bfb35cb977678daf5c56c1531e6 and restores an old version of recastnavigation, most likely https://github.com/memononen/recastnavigation/commit/1be9de72d87dcfdecf6bea30f5461745f7d7afe6 .

Re-extracting MMAPS is required.
Core/PlayerDump: fix mail items and gifts export
Merge pull request #15 from TrinityCore/master

pull