[controller] cleanup old code
improvement for seaf-fsck
Merge pull request #813 from Chilledheart/cleanup_patch_1

[controller] cleanup old code
Merge branch 'fsck' into 3.1
[server] Improve output messages for seaf-fsck.
Fix build problem for lib/Makefile.am.
[common] use packed attribute if available
[build] Add CMake Build System

  - remove key storage stuff
  - python support
  - support for new-sync
[cleanup] silence multiple compiler warnings

  - silence the warning of uninitialized head_id in putcommit-v2-proc.c
  - silence the warning of implicit declaration of g_open in test-seafile-fmt.c
  - silence the warning of implicit declaration of g_stat in test-cdc.c
  - silence the warning of uninitialized e in merge-recursive.c
  - silence the warning of bm->size >= 0 is always true in fileserver.c
[lib] add seaf_daemonize
[client] cleanup unused code