Indexing/index settings improvements:

- Add support for custom index settings in config (updates without full reindex).
- Flag index dirty instead of reindexing immediately after product import.
- Skip delete operations for disabled stores.
- Fix broken clean index.
- Remove unnecessary resetSearchResults (caused huge database load after
  mass actions).
- Make indexing product count optional.
- Do not full reindex on product/category delete.
Fix foreign key errors related to deleted products.
Merge pull request #49 from colinmollenhour/indexing

Indexing/index settings improvements:
Merge pull request #48 from colinmollenhour/save-last-query

Use cookie to save last query (optional feature disabled by default).
Fixed syntax error
Fixed syntax error
Fixed syntax error
Add 1.0.2 stable release
Fix and improve search results processing.

- Fix deadlock that may occur with order processing.
- Fix results saved every search (remove flag probably added for debugging).
- Add results limit configuration.