Untested command to download l-packs from central server
Command works with exception of updating database
New language pack schema works for admin; simplified code based on PR comments.
Updated download command and models to reflect new schema (handles software version)
Documented LanguagePack model; Added defaults for languagepackdownload command.
Documented LanguagePack model; Added defaults for languagepackdownload command.
Merge branch 'download_languages' of github.com:dylanjbarth/ka-lite into download_languages
Added custom migration to support new schema, updated languagepackdownload command's pack creation to work.
Altered language code max length to be 8; created migration file to reflect this.
Merge pull request #864 from dylanjbarth/download_languages

Distributed server management command to download, unpack language packs, and update database to reflect newly installed languages