SphinxSearch engine default values uniformisation
Fix search engine suggestions usage
Use phraseanet configuration for sphinx search engine tests
Merge pull request #558 from romainneutron/search-engine

[3.8] Search engine fixes
Update media dependencies
Merge pull request #557 from nlegoff/fix_1413

[3.8] Fix #1413 Add possibility to delete a persistent session
Merge pull request #560 from nlegoff/fix_alert

[3.8] Fix #1411 Cannot close alert
Merge pull request #561 from romainneutron/media-dependencies

[3.8] Update media dependencies
Move substituion logger from class method to controllers
Fix #1414 Add immediate thumbnail substitution after success download
Fix CS
Use temporary file system
Fix & enhance unit tests
Adressed @romainneutron 's comments