#36 bind lowerBoundary to upperBoundary and vv

use the previous-interval binding to bind the indicatorValue of the
lowerBoundary to the upperBoundary and vice verca. the previous-interval
binding was introduced to determine the labels in the interval. using
the previous-interval binding is not in the proper meaning of the
binding, but avoids inroducing a new binding.
close #36 regard de-/increasing indicator values

the upper and lowerBoundary now check if the indicator values are de- or
increasing and use the corresponding label (<=, >=)
Merge branch 'feature/36-criteriaFunction-labels' into dev
 #37 changed direcive interface

the criteriaFunction manager now binds to a set of worldstates from
which it extract the indicators instead of a set of indicators directly.
 #37 updated bootstrap to 3.2.0

in bootstrap 3.2.0 the disabled class for list items is added. this
class must be used to disable the criteria function and decision
strategy list items
 #37 disable criteria function items if no worldstates
close #37 disable decision strategy items when no worldstates selected
Merge branch 'feature/37-disabled-list-items' into dev
fixed #38
Merge branch 'bug/38-criteria-function-interval-tooltip' into dev