key_empty now depends on the underlying garray being empty
Added test "macros" to lex2.pl and used in testing trie

- possibly malfunction in trie
Added a drop-db command line option to tagfs
Completed movement of common data into abstractfile struct member

- removed the awful buffer passing for extracting file names. They are
  only used in a const fashion and can be copied _when needed_.
- fixed an issue with double locking in abstract_file.c
- enhancement to cunit string equality tests
Added tests

- Removed debug print statements
Moved key sorting out of trie into stage

- added an option for choosing the database file
- added very simple acceptance tests
Removed obselete subfs
Switched to a hash table based stage
Apparently corrected memory leak in readdir

- Was causing block with sem_wait in file_name_cmp
Adding key and stage tests