Compatible with 1.7.5 and do some fixes...

[Add]
-Add an new option in the config, timeOnChair.
-Add compatibility with craftBukkit 1.7.5.
[Fixes]
-Some fixes in the command spp.
-Do some fixes in the method of custom msg.
-Some other fix on the taskSitOnChair call.
Merge branch 'master' of https://github.com/como89/SleepingPlus