PICKED FROM TRUNK 21134

fix for SCHEDULING-1430
- PAwaitFor : temporary files are now stored in a subdirectory of temp directory .PAscheduler containing the id of the PAsolve call. Cleaning of the temporary files is now done via a silngle "rmdir" call rather than many "delete".
- PAsolve :
1) Improvement of find dependency speed : a function database is now built after checking dependencies, if a function has already being checked, the analysis is retrieved instead of starting a new one
2) Improvement of creating source zip files. Now a single zip file is created for a given list of source files, a hash is computed on the list of sources files. Thus, if the same list appear again, the same zip file is reused instead of creating a new one.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/proactive/scheduling/branches/Scheduling_3.1.x@21140 28e8926c-6b08-0410-baaa-805c5e19b8d6