1) Split MdePkg/Include/Library/PiLib.h to DxePiLib.h and PeiPiLib.h. These two library classes are for DXE phase and PEI phase.
2) Update the API names in DxePiLib and PeiPiLib to be longer ones to be more meaningfull and to avoid name collisions.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4067 6f19259b-4bc3-4df7-8a09-765794883524