Add FLAC standalone indexer
Add indexing common music tags for all formats supported by taglib
File indexer reindex files that have been indexed by older versions of
the indexer and reindex them
Sparse improvements to deep indexing
ATM it support extracting metadata only from OGG files.
The system has been designed to be easly extensible to more file formats
registering more indexer functions which just need to extract metadata
from a certain type of file and feed it to Xapian.
The system has been integrated into existent file search system to
through generric search requests and results, it keep a good level of
retro-compatibility due to some tricks.
The indexing system is released under AGPLv3 so when libretroshare is compiled
with deep search enabled AGPLv3 must be honored instead of LGPLv3-or-later.
Cleaned up the debian copyright file using non-deprecated license
code-names.
