changed re-hashign strategy. Now uses in priority the system time of the index file as a reference for new files. This automatically accounts for changes in system time and fixes the re-hashing bug for daylight changing time. In case the reference time cannot be establishd, the comparison reverts to the old method. This change is backward compatible and should not cause a re-hash. Report to the devs if it does.

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6895 b45a01b8-16f6-495d-af2f-9b41ad6348cc
removed false warning that come up when openning a non existing file in ftFileCreator.

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6896 b45a01b8-16f6-495d-af2f-9b41ad6348cc
Changes according to experiments from jolavilette:
- set desiredRate of peers to 10MB/s instead of 1MB/s
- maximum number of active chunks per peer is now 20 (that was a serious limiting factor)
- ticks that bring no data are not accounted for in the speed estimate anymore. The data is averaged over all ticks since the previous 
 non zero data chunk -> this brings much more stability to sources and removes lots of oscillation.

The maximum theoretical speed per source peer is therefore 13MB/s (in "Average" DL mode), whereas previously it was 1.3MB/s



git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6897 b45a01b8-16f6-495d-af2f-9b41ad6348cc
removed debug output

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6898 b45a01b8-16f6-495d-af2f-9b41ad6348cc
computation/update of routing probabilities

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6899 b45a01b8-16f6-495d-af2f-9b41ad6348cc