Achieved and being tested a large set of improvements :

- User records indexation :
indexes three new documents
-- User description, indexes all users with description (could be pursued)
-- User blog posts, indexes the posts using subject, abstract and content
-- User blog attachments, depending on physical file indexability

- Assignement indexation
indexes assignement descriptions
tries to index assignment submission, but architectural issues on multiple uploads (in progress)

- Search API pluggability improved
-- allows detecting searchable third-party plugins, and delegates to plugin the search related implementation
-- Techproject spitted out from core search strategy, as being third -party. Used for testing above

- Extensible physical handling
-- allows adding configuration parameters to launch converters without having to modify config_global.htm
Note : it is still necessary to code and add a physical_XXX.php handler in /search/documents

- Enhanced indexer configuration
Allows to enable or disable by configuration modules to be indexed. This adds a great deal of flexibility in indexer, and allows disabling locally struggled components. (Asked by Matt Gibson in MDL-12271)

- UTF8 fixes and straithening
Forces to construct UTF8 compatible Lucene instances
Checks UTF8 back links
Fixes an UTF8 issue in querylib.php avoiding searches with special utf8 chars to match

In progress :
Tests on 1.9

Question : how to proceed for commitments ? I suggest commiting in HEAD before code review, and wait feedback for stability status.