Enables extended locking styles.
Normally, SQLite running on a Unix-like system will use POSIX
fcntl() based locks for
all files. If this parameter is defined, SQLite will change its
locking style depending on the type of filesystem it is using.
This flag only has significant effects under Mac OS X, where it
is enabled by default. See the SQLite website for more details
(http://sqlite.org/compile.html#enable_locking_style).