Close the database before reading its contents

In Database.export, the contents of the database has to be flushed to
the db file before the contents of the file are read and returned.

Fix #9
Fix #55

coffee/api.coffee

@@ -374,8 +374,13 @@ class Database
 	### Exports the contents of the database to a binary array
 	@return [Uint8Array] An array of bytes of the SQLite3 database file
 	###
-	'export': -> FS.readFile @filename, encoding:'binary'
-
+	'export': ->
+		stmt['free']() for _,stmt of @statements
+		@handleError sqlite3_close_v2 @db
+		binaryDb = FS.readFile @filename, encoding:'binary'
+		@handleError sqlite3_open @filename, apiTemp
+		@db = getValue apiTemp, 'i32'
+		binaryDb
 
 	### Close the database, and all associated prepared statements.