removed out of place error message that showed when clicking on signs placed on fields
moved preciousstones.admin.info into preciousstones.benefit.info.  admins can see info for all fields like before, but players now will be able to see who the fields belong to by using the command instead of having to click on the ground.
increasing lines per page, unecessarily small with chat scrolling
fixed issue where [shared] sign would stop responding after first interaction
fixed issues with sign warning being sent out at seemingly wrong times

fixed issues with sign warnings being sent out when using similar signs from other plugins

added default item currency setting (settings.default-item-currency) for rent/buy/share signs to be used when players fail to write an item with parenthesis on the currency line (and no economy plugin is installed)
shared rent signs now displays the remaining rent time just like the rent sign does.  it will display the time remaining that the renter which is closest to the block has.
(closes #754)