Added reference to IOLTS paper

See merge request !6

Update README.md

See merge request !5

add questa ci

See merge request !4

Ft/spyglass ci

See merge request !3

Merge previous to the public release of the repo

See merge request !2

# Conflicts:
#   LICENSE

Add two generics to add registers at the stall outputs and at the
instruction counter inputs. The number of the generic is the number of
consecutive registers that will be instanciated.

Change names to make the coehirent with the documentation. Add
documentaion (GRLIB manual).

Add the API with SafeDE c library. Remove slack_handler_max so max and
min staggering are configured always. If max staggering is not
configured trhough the API it will get its maximum value.

Change the way core1_ahead_core2 is computed

Delete comparator module as it is not needed for the final version. The
comparator will remain in other branch in case the project of a
tight-lockstep is done. Add max_slack_handler module, so can be chosen if an
upper threshold wants to be configured.

Add comments and clean up previously to delete de comparator module and
prepare the version to be finally integrated in SELENE.