When -a is passed (always sync) open the storelog with O_SYNC.

Makes us able to skip calling cyon_storelog_sync() every write.
Also reorder the way we write the storelog and do one single write
call with all the required information instead of 2 write calls.
Lock the store when flushing the logs
Add -d mode (Disk mode) causing Cyon to read/write all data from/to a O_APPEND
file instead of retaining in it memory. Useful for long term storages.

Fix an issue where fsync() would be called constantly when trying to
flush log file.

Fixed an issue where the store write could crash if the server was
under heavy load from multiple concurrent clients.

Stuff's good.
Remove leftover debug.
Handle corrupted log files better, add readonly mode.
If log corruption is found, readonly is turned on.
Time for an update
More
Allow cyon to save log states (-l), which can be applied
to slaves. Determining the correct order should be as easy
as taking a look at the current store its actual SHA1 hash
where the hash is calculated from (store len - SHA1_DIGEST_LEN).

A simple tool to replay these logs to replicas should be written.
Write the stores properly, so they are all exactly the same on each machine.
Spacing