Added direct compatibility with PlaceHolderAPI plugin. You can check full list of placeholders at https://github.com/Zrips/Jobs/wiki/Placeholders and keep in mind that they are different from PAPI provided ones and starts with jobsr as of Jobs Reborn to avoid confusion when some placeholders will not work and we will have to figure out which plugin is responsible for that.
Added new command /jobs placeholders (parse) (placeholder) to check full list of possible placeholders and if needed option to parse and check what it would result into.
Some fixes related to block slab type on older versions introduced with latest version.
Some extra try catch when disabling plugin to continue plugin disabling even if something goes side ways with one or another module while doing that.
