Region updates

Redefine region type as Mainland or Estate
 - Mainland regions are owned by the RealEstate owner and part of the
system 'Estate'
 - Simplified region creation to provide a 'standard' setup
 - Added as region Terrain (type) identifier
Updated checking for System Estate to revise existing (if any) correctly
WebUi updated region info to provide both Type & Terrain
WebUI 'Viewer Help' update

- Add Kokua viewer images
- Remove Imprudence, Phoenix & Zen viewers
- Reformat and add website links
WebUI - Registration update

- Check configuration 'AllowAnonymousLogins' setting for registration
access (in additional to the web setting)
- Trap invalid avatar archive directory search
Inventory archiver (IAR) updates

PathHelper Updates
- VerifyReadFile / VerifyWriteFile
InventoryArchiverModule
- Update IAR load and save
- Load / save to 'Data'UserArchives' folder
InventoryArchiveUtils
- Create user default inventory if it does not exist for a search
Merge branch 'master' of https://github.com/WhiteCoreSim/WhiteCore-Dev

Conflicts:

WhiteCore/Modules/World/Startup/SimulationData/FileBasedSimulationData.c
s
Inventory archive (IAR) updates

- Ignore viewer folders on save (#<viewer>)
- Additional checks for available inventory details
Region initialisation updates

- Added additional terrain preset types (Private, Homestead, Openspace)
with varying parameters