Tools/MeshExtractor: Fixed a lot of stuff, finally made the Doodads render, the WMO's have been disabled for now.
ToDo:
* Fix the doodads positions.
* Review and re-implement some code.

P.D: Help me please.
Tools/VMAP Extractor: Fix memory issues

Fix not-NULL terminated char buffer and uninitialized memory written to vmaps due to WMOLiquidHeader struct padding bytes left uninitialized. The padding bytes should be ignored anyway by VMAP Assembler so no re-extraction is required.

Valgrind log:
 Syscall param write(buf) points to uninitialised byte(s)
  at 0x585FB50: __write_nocancel (syscall-template.S:81)
  by 0x57EE2F2: _IO_file_write@@GLIBC_2.2.5 (fileops.c:1270)
  by 0x57EE1D1: new_do_write (fileops.c:546)
  by 0x57EF904: _IO_do_write@@GLIBC_2.2.5 (fileops.c:519)
  by 0x57EEB70: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1341)
  by 0x57E3EC4: fwrite (iofwrite.c:43)
  by 0x41161B: WMOGroup::ConvertToVMAPGroupWmo(_IO_FILE*, WMORoot*, bool) (wmo.cpp:386)
  by 0x407FA9: ExtractSingleWmo(std::string&) (vmapexport.cpp:215)
  by 0x407B16: ExtractWmo() (vmapexport.cpp:138)
  by 0x409D50: main (vmapexport.cpp:497)
 Address 0x40398e2 is not stack'd, malloc'd or (recently) free'd
 Uninitialised value was created by a heap allocation
  at 0x4C2C7A7: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  by 0x410ADA: WMOGroup::open() (wmo.cpp:224)
  by 0x407F54: ExtractSingleWmo(std::string&) (vmapexport.cpp:208)
  by 0x407B16: ExtractWmo() (vmapexport.cpp:138)
  by 0x409D50: main (vmapexport.cpp:497)
Core/RBAC: Simplify RBAC implementation
- Drop groups (roles than can have inherited roles) and roles (set of
  permissions)
- Permissions can now have inherited permissions (those act as roles)

RBAC DB structure is now limited to four tables
- rbac_permissions: Contains permissions and roles
- rbac_linked_permissions: Contains the relation between permissions and
  linked permissions (those permissions that have linked permissions are
  called roles)
- rbac_default_permissions: Contains the list of permissions to be granted
  to each security level [Added to maintain compatibility in an easy way]
- rbac_account_permissions: Contains the list of permissions granted or
  denied for a particular account.

NOTE: IF YOU ARE USING CUSTOM PERMISSIONS, ROLES OR GROUPS CHECK THE SQL
BEFORE APPLYING...
Fix compile under linux and update auth db with latest changes