Cleaned up AST.h.
Cleaned up AST.h.

* Added some regions make the code easier to work with.
* Moved related things together.

zillemarco/CppSharp,imazen/CppSharp,u255436/CppSharp,u255436/CppSharp,mydogisbox/CppSharp,mono/CppSharp,xistoso/CppSharp,ktopouzi/CppSharp,u255436/CppSharp,txdv/CppSharp,ktopouzi/CppSharp,inordertotest/CppSharp,mydogisbox/CppSharp,zillemarco/CppSharp,u255436/CppSharp,genuinelucifer/CppSharp,KonajuGames/CppSharp,xistoso/CppSharp,inordertotest/CppSharp,Samana/CppSharp,SonyaSa/CppSharp,mydogisbox/CppSharp,KonajuGames/CppSharp,mydogisbox/CppSharp,nalkaro/CppSharp,xistoso/CppSharp,imazen/CppSharp,inordertotest/CppSharp,imazen/CppSharp,nalkaro/CppSharp,Samana/CppSharp,inordertotest/CppSharp,zillemarco/CppSharp,genuinelucifer/CppSharp,imazen/CppSharp,genuinelucifer/CppSharp,xistoso/CppSharp,KonajuGames/CppSharp,SonyaSa/CppSharp,imazen/CppSharp,nalkaro/CppSharp,nalkaro/CppSharp,mono/CppSharp,u255436/CppSharp,mohtamohit/CppSharp,ddobrev/CppSharp,SonyaSa/CppSharp,SonyaSa/CppSharp,mohtamohit/CppSharp,SonyaSa/CppSharp,genuinelucifer/CppSharp,nalkaro/CppSharp,ddobrev/CppSharp,inordertotest/CppSharp,zillemarco/CppSharp,zillemarco/CppSharp,genuinelucifer/CppSharp,ddobrev/CppSharp,txdv/CppSharp,Samana/CppSharp,ddobrev/CppSharp,Samana/CppSharp,txdv/CppSharp,mono/CppSharp,txdv/CppSharp,KonajuGames/CppSharp,mohtamohit/CppSharp,txdv/CppSharp,ktopouzi/CppSharp,Samana/CppSharp,ktopouzi/CppSharp,KonajuGames/CppSharp,mono/CppSharp,ddobrev/CppSharp,ktopouzi/CppSharp,mydogisbox/CppSharp,mohtamohit/CppSharp,xistoso/CppSharp,mono/CppSharp,mohtamohit/CppSharp,mono/CppSharp