general database classes instead of sqlite specific code 
database: set a number of paths to default index. will require an indexer code though
sandboxing!
allow from GUI to ues commandlin, e. g. "/add ..." would be the same as "qss add ..." in termial

PdfPreview: Use some kind of paging instead of memory limit
Consider injecting Logger (default stdout/stderr) to classes instead of using Logger::info()/Logger::error()::
sync/share GUI and CLI data-structures. Better to share codebase in general
- cli: tagging
- cli: command line parser: wrong position of [options] 
- ability to set the WHERE condition (allow editing the SQL query)
- Basic OCR in images (screenshots)
- Index .ebup
- Preview for: .txt, source code files, .ebup, images
- index: DVD menus, media metadata in audio/files etc?
- Stats: Number of results found
- PdfPreview: Files per file, or directory (so basically filter the 
results)
- Hide PdfPreview Tab if there are no pdfs in the results
-Tagging: add an "addtag" utility, to assign tags to folder and files
-gui: Search expclitly for tags, list by tags, remove tags, add tags
-gui: Filter already found results. For example, "show only folders",
or just search with those results.
-split each tab into own class, not everything in mainwindow.cpp?
Menu:
-Delete from index
-Delete from fs
-Reindex
Filter:
type:d 
type:file
mtime:
tag: