In the CI web app API add support for counter
This is to require a new command in the CI web app API that allows to increase/decrease the value of a variable.
The variable will be of the same type on the variable used as statistic.
The user will initialize the value of the variable.
The new command will require 2 arguments: the name of the variable and the value of the increment (this could be any value, positive or negative).
This variable can be used as counter and its value will be showed in the "testname" view with the current value.
The user should be able to use as many counters as needed.