Fix paver python prereq paths
Updates to problem location for opaque keys
Remove package_id and remove lower_ stuff from migrator
STUD-1603
added and updated pavelib/quality.py from dglance branch, deprecated rake quality tasks
fix for pylint/pep8 defaults
i18n: Make values that has 'display_name' be displayed localized in editor

Dictionary values like Boolean, or some other value types which has 'display_name' can now be displayed with the localized version.
Merge pull request #3859 from edx/clytwynec/rake2paver-quality-take2

Clytwynec/rake2paver quality take2
copied from LMS aws_migrate settings
Fix gen_cert_report to use CourseKeys.
Merge pull request #3890 from edx/derf/parameterize_cms_migrations

copied from LMS aws_migrate settings
Merge pull request #3889 from edx/diana/fix-gen-cert

Fix gen_cert_report to use CourseKeys.
Updated changelog
Merge pull request #3891 from edx/flowerhack/changelog

Updated changelog
Cheatsheet visibility code refactored.
Merge pull request #3847 from edx/waheed/cheatsheet-code-refactor

Cheatsheet visibility code refactored.
Merge pull request #3842 from edx/ahodges/documentation/LMS2748

Updates to problem location for opaque keys
Merge pull request #3745 from edx/dhm/no-package-id

Dhm/no package
Merge pull request #3899 from edx/opaque-keys

Opaque keys
Fixed change log table format & pdf errors
Merge pull request #3875 from louyihua/translation-fix

i18n: Make values that has 'display_name' be displayed localized in editor