Using Bootstrap for index/edit/view/add pages for the correct branch

This branch copies over the changes in phoenix/feature/theme so that they can be merge with phoenix/develop

This branch currently modifies a few Twig templates, CakePHP FormHelper and PaginatorHelper. Everything in this branch has been baked using cdli_new_-July 23, 2019.sql database.

Overwritten

These controllers and their corresponding templates have been overwritten using bake only. (The second group had slight changes in columns):

Abbreviations, ArtifactsCollections, ArtifactsComposites, ArtifactsExternalResources, ArtifactsGenres, 
ArtifactsLanguages, ArtifactsMaterials, ArtifactsPublications, ArtifactsSeals, ArtifactsShadow, 
CdlNotes, Collections, EntryTypes, Journals, MaterialAspects, 
MaterialColors, Regions, RetiredArtifacts

Archives, ArtifactTypes, Genres, Months, Materials, Languages, Inscriptions, 
ExternalResources, Periods, Proveniences, Publications, Rulers, Years

Newly added

These did not previously existed and were newly added:

ArtifactsDates, AuthorsPublications, Dates, Dynasties, PostingTypes, Postings

Manually updated

These were manually revamped to use Bootstrap now:

Users, Authors, Artifacts (view.cpt untouched), Credits, Register, Twofactor, Twofactorlogin

A few of the controllers were not found in the new database. These have not been overwritten and a issue will be raised soon. Additionally, Artifact view.cpt has not been modified and is the same as before. See #49 (closed). See !23 (closed) for the unmerged PR of the old branch.