a linkedlist class of type task

this is a generic linkedlist provided by java. right now have functions
of adding a task, deleting the first occurence of a task, deleting by
index and obtaining the whole list. its static and can be used by other
classes
update: linkedlist class of type task

functions: add task, delete by task, delete by index, size, get task by
index,.
update: linkedlist clas of type task

use object to access this
Merge commit '1c518e5a9e8f76a0816155948c373cfd052ba56a'