[server] don't echo admin password in setup-seafile.sh
Modify README
[server] add 1.6 upgrade script
[server] add mysql upgrade sql
removed msi/README.markdown
[server] support customize seafile-data location in seafile-admin
[server] monitor httpserver in controller

monitor pid instead of heartbeat messages
[server] fixed a bug in controller
[server] controller don't remove pidfiles when exit
[server] improve controller

Don't restart process if reading pidfile failed, except with ENOENT
[client] Improve GC performance.

Separate commit pointers for uploaded commit and checked out commit.
It's not correct in some cases to use one pointer for both, such as
when merge fails.
[client] Make sure only one seaf-daemon instance can run.
[client] Fix a few bugs.