The sqlite configure script guesses whether to enable Tcl support. Apparently,
this guessing finds a Tcl installation in /usr and thus enables Tcl. The
subsequent build fails, however: the compiler doesn't find the <tcl.h> because
/usr is not a default search path. To remedy the problem, the expression now
explicitly specifies --disable-tcl to avoid guessing altogether.
In the same spirit, we furthermore specify the following configure flags, which
represent the defaults that ./configure chooses when left on its own devices:
--disable-amalgamation
--enable-threadsafe
--disable-cross-thread-connections
--disable-tempstore
svn path=/nixpkgs/trunk/; revision=16184
438d023eee