Update Punic to the latest version

#804 requires the latest version of Punic. I forgot to update composer.lock in #804
making external form block work again
Merge pull request #809 from mlocati/update-composer-lock-for-punic

Update Punic to the latest version
Removing Chosen in favor of select2
Merge branch 'master' of github.com:concrete5/concrete5-5.7.0
adding select2 to the search dialgos
Fix #768; Fix #810
making full page caching work again