adds option to search for particular plugin directories
use ASUtils to locate plugin migration directories
use ASUtils to locate plugins when initializing
add plugin assets to rails pipeline in production as well as development
Merge pull request #11 from lcdhoffman/plugin-migrations-patch

Plugin migrations patch
EAD export: change DAO href mapping

Use the first `file_version.file_uri` if available; otherwise
use the `digital_object.digital_object_id`
Merge pull request #12 from anarchivist/dao-uri-mapping

EAD dao mapping changes
Remove unecessary require statement [ci skip]
Add stub stylesheets directory [skip ci]
Change AppConfig :report_page_size to :report_page_layout

* The AppConfig[:report_page_size] config variable was not used.
* Change AbstractReport#orientation method to AbstractReport#layout.
* AbstractReport#layout now returns AppConfig[:report_page_layout]
* Add a few extra comments to config-defaults.rb for info.
Merge pull request #13 from anarchivist/report-layout

Change AppConfig :report_page_size to :report_page_layout
Parallelize Travis suite

Runs dist task, unit/integration tests, and Selenium tests as three
separate suites. We were often running into timeouts before because
of Travis-CI's hard 50-minute cap.

Also make setting some of the environment variables a bit cleaner:
INTEGRATION_LOG_FILE, SCREENSHOT_ON_ERROR, and JAVA_OPTS (used to
pass the MySQL JDBC connection string).
Merge pull request #14 from anarchivist/parallelize-travis-once-and-for-all

Parallelize Travis suite
Add prefix to ensure ref_ids are valid in EAD
EAD export: only add <address> tag if there is an address
EAD export: revise extent mapping and handle empty component IDs
EAD import: map physdesc only to Extent, not to Notes
EAD export: don't insert <ref/> when reference_text is empty
Merge pull request #15 from anarchivist/ead-export-tweaks

EAD import/export tweaks (thanks to Mark Custer for feedback)
EAD import: handle @otherlevel and unset @level attributes on components