Rename database file

Because schema is completly redone and the old filename was not
informative. File extension .sqlite3 is recommended by SQLite
developers. Edit README accordingly.

README.md

@@ -2,9 +2,9 @@ Tag your files
 ======================
 
 `ftag` is a command line tool to tag files. Strings are associated to
-file names in a database file called `.ftagdb`. Files can later be
-searched for by tag names. Unix-like systems are supported (eg. OS X
-and Linux).
+file names in a database file called `.ftag.sqlite3`. Files can later
+be searched for by tag names. Unix-like systems are supported (eg. OS
+X and Linux).
 
 How to compile
 -------------
@@ -24,12 +24,12 @@ use. A more complete reference can be found using the --help option.
 * `ftag list FILE`: Print all tags associated with the file FILE on
    stdout.
 
-Important to note is the location of the database file (`.ftagdb`). 
-When the application is run it will search for this file starting
-from the current directory ascending towards the root directory. If
-no database file is found it is created in the current directory.
-Which database file to use can also be specified with the -d,
---database-name and -p, --database-dir options.
+Important to note is the location of the database file
+(`.ftag.sqlite3`). When the application is run it will search for
+this file starting from the current directory ascending towards the
+root directory. If no database file is found it is created in the
+current directory. Which database file to use can also be specified
+with the -d, --database-name and -p, --database-dir options.
 
 Contact
 -------

ftag.c

@@ -39,7 +39,7 @@
 /***--- Constants and globals ---***/
 
 #ifndef DB_FILENAME
-#define DB_FILENAME ".ftagdb"
+#define DB_FILENAME ".ftag.sqlite3"
 #endif
 
 #define PROGRAM_NAME "ftag"