Provide possibility to register callbacks that are called from InitGlobals and DoneGlobals.

globals.pas:
  + new function register_initdone_proc which allows to register a callback for InitGlobals and DoneGlobals respectively
  + add functions callinitprocs, calldoneprocs, allocinitdoneprocs, freeinitdoneprocs to manage and access the init/done-callbacks
  * InitGlobals: call callinitprocs
  * DoneGlobals: call calldoneprocs 

git-svn-id: http://svn.freepascal.org/svn/fpc/branches/svenbarth@28693 3ad0048d-3df7-0310-abae-a5850022a9f2